Through a Glass Darkly: Journeys through Science, Faith and Doubt – A Memoir (2020)

Description: In Through a Glass Darkly Professor McGrath shares at length and for the first time how exactly he moved from atheism to faith while studying natural sciences at Oxford University, and how each discipline has informed the other throughout his life. This is a rich, inspiring read from one of today’s greatest public theologians.


Alister McGrath has written an intellectual thriller that documents his transition from a nature-loving schoolboy Marxist to the Oxford Professor of Science and Religion. The detail is fascinating: discovering that what once was certain crumbled, probing the methods and limits of science and finding in literature, historical, philosophical and imaginative, a pathway from the shadows of Plato’s cave to an epiphany of understanding in the sunlit uplands, similar to that of C.S. Lewis before him. Realising not only that science and religion give different but complementary maps of the world, but also that Christianity offers the coherent big-picture framework for which his mind and heart had been questing. This is a must read for all those interested in the life of the mind and the science-religion debate. I could not put it down. You will not be able to either.

— John Lennox, Emeritus Professor of Mathematics, University of Oxford

‘A compelling story, at once readable and profound. In charting his path from atheism to Christian faith, Alister McGrath offers rich resources for believers, as well as a robust challenge to sceptics and religion’s cultured despisers.’

— Rupert Shortt, author of Outgrowing Dawkins: God for Grown-Ups

Alister McGrath is renowned as a world-leading academic and very successful author with a particular interest in the interface of science and religion. This readable account tells his personal story and might even become a classic. It portrays his journey from a young prodigy to scientist and theologian. Enlivened with occasional flashes of humour and drawing on the author’s exceptional breadth and depth of reading, it illustrates why he has successfully written for popular as well as academic audiences. It deserves to be very widely read.

— Michael J. Reiss, President, International Society for Science and Religion

A personal story of how Alister McGrath travelled from a youthful certainty of atheism, across troubled intellectual seas, to arrive on an island of faith where he learned to be at peace with uncertainty . . . McGrath explains why Christianity, in providing the big picture which accommodates science, is not only plausible but intellectually satisfying. Through a Glass Darkly is a book that will help anyone wishing, with sincerity and intellectual honesty, to reconsider the apparent conflict between science and Christian faith.

— Paul Ewart, Professor of Physics, University of Oxford

On being a “meaning junkie”

Human beings thrive on “big pictures” – ways of looking at the world that help them construct meaning, value and identity in life. Some of these are religious; others are not. Psychological research suggests that we function better when we have a sense of meaning and purpose. It’s not a new idea. The great Spanish philosopher José Ortega y Gasset (1883-1955) declared that we need a “big picture”, an “integral idea of the universe” if we are to flourish as human beings. That doesn’t make this quest for meaning right – but it certainly means that it’s natural. Maybe we are “meaning junkies”, whether we like it or not.

I didn’t read Ortega until late in my career. Yet even as an undergraduate studying chemistry at Oxford University I had grasped the point he was getting at in some of his core writings. I’ve loved the sciences since I was at high school. When I was 9 or 10, I built a little telescope to look at the night sky, and took delight in seeing the moons of Jupiter for the first time. What excited me even more was that their orbits could be described so accurately with elegant mathematical equations. It was as if the beauty of nature was enhanced by the equally beautiful mathematical representations of the world. Yet it seemed to me that something was missing from a scientific account of nature. Scientific truth was precise, but it was incomplete.

For Ortega, any philosophy of life or way of thinking about the questions that really matter will end up going beyond science. Why? Not because there is anything wrong with science. The point is that science works so well because it is so focussed and specific in its methods. Ortega suggested that the “admirable qualities” of science include its “precision and the certainty of its predictions.” Yet these virtues are achieved at a price. Science leaves “ultimate and decisive questions untouched.” As human beings, we need more than science is able to deliver. Scientists are human beings, and are just as concerned about what Karl Popper termed “ultimate questions” as anyone else.

The Nobel laureate Sir Peter Medawar (1915-87) argued that there were “questions that science cannot answer and that no conceivable advance of science would empower it to answer”.  He had in mind questions about the meaning of life and morality. Now Medawar might be wrong on this (although most attempts to construct a purely scientific basis for morality – such as Sam Harris’s recent Moral Landscape – have failed to deliver convincing answers). But suppose Medawar was right. Scientists think and care about these big questions as much as anyone else. If science can’t answer them, they’ll just look for answers elsewhere, in the worlds of metaphysics and faith.

In my recent book The Big Question, I explore the question of whether science and religion can each be thought of contributing part – but only part – of a “big picture”. Neither is adequate for our needs on its own; together, they can offer an enriched vision of reality. This is not a new approach. It goes back to the Renaissance, although it has been updated to take account of the changing intellectual culture of the twenty-first century.

Like the philosopher Mary Midgley, I take the view that reality is so complex that no single research method is good enough to engage its many facets. We need a rich palette of colours to represent the complexities of our observations of the world around us, and our experience within us. “For most important questions in human life, a number of different conceptual tool-boxes always have to be used together.” In The Big Question, I look at two classic ways of developing this idea. The first is the idea of “multiple maps of reality”, based on the idea of the accumulation of multiple perspectives on our world to give a richer and deeper picture than any single approach offers.

The second is multiple “levels of explanation,” which recognizes the stratification of physical and social reality. The geologist Frank H. T. Rhodes, who served as President of Cornell University from 1977 to 1995, using the analogy of a boiling kettle to explore the idea. One explanation was energy conversion, which raised the water in the kettle to boiling point. Another was that he wanted to make himself a cup of tea (Rhodes, I should add, was British). The basic idea is simple: these are complementary, not competitive explanations, building up to give a fuller understanding of the phenomenon under discussion.

I realize that many readers of this blog will be uneasy about this kind of approach. After all, science and religion are meant to be locked into permanent warfare. Allowing them to talk or interact like this seems pointless, even delusional. I recognize such concerns, which I once shared myself. Yet the old stereotype of the “warfare” of science and religion has crumbled in the last three decades, as historians have demonstrated that the relationship is much more fluid and complex than it allowed. The New Atheism raised lots of good questions about this relationship, but offered answers that just don’t seem to work, intellectually or existentially. We need to explore other options.

In The Big Question, I explore a way about thinking about science and faith which I believe holds them together in a way that is both rationally satisfying and imaginatively exciting. I can’t prove my approach is right, but I can assure you it is deeply satisfying, and well worth exploring.

But there are more questions that need to be asked. One of the things I love about science is not merely that it is open-ended; it is never-ending. When you think something has been settled, you find that a whole new series of questions are opened up. We inhabit an “island of knowledge” (Marcelo Gleiser). Yet, like Isaac Newton before us, we cannot help but wonder what lies beyond its bounds. As we walk around its shorelines, we stumble across things that suggest there is more to know, at the moment tantalizingly beyond our grasp. Maybe Newton himself might inspire us to keep looking, and keep wondering.

“I seem to have been only like a small boy playing on the sea-shore, diverting myself in now and then finding a smoother pebble or a prettier shell than the ordinary, whilst the great ocean of truth lay all undiscovered before me.”

Alister McGrath is Andreas Idreos Professor of Science and Religion at Oxford University, Director of the Ian Ramsey Centre for Science and Religion, and Gresham Professor of Divinity. He holds three earned Oxford doctorates in the fields of molecular biophysics, Christian theology, and intellectual history. His most recent book is The Big Question: Why we can’t stop talking about God, Science, and Faith (New York: St Martin’s Press).

Science, God, and Life

I fell in love with astronomy when I was ten years old. I didn’t really understand the science of the heavens, but I could grasp the beauty and wonder of the night sky, wondering what it was all about. My experience of wonder made me want to know more about the planets and stars, and was an important motivation in my decision to focus on science. I had no interest in religion, and in my teens became an aggressive atheist, holding that science alone was able to answer all of life’s questions. Yet I still found myself fascinated by the night sky, drawn by its vastness and austere beauty.

I remember well reflecting one winter’s evening on the ‘Belt of Orion’, three bright stars at the centre of this constellation, which was a prominent feature of the Irish night sky in December and January. I knew enough about those three stars to know that they were very distant. In fact, I was seeing these stars as they had been hundreds of years ago, not as they actually were.

This, of course, was a simple scientific fact. Yet it was as if I had appreciated its existential implications for the first time. I realized the insignificance of my own lifespan in comparison with the vast distances and timeframes of our universe. It was a moment of insight, in which I came to see that I was unable to cope with the fact of my mortality. I would not be alive when the light being emitted from those three stars finally reached the earth. However, I took the view that science determined what was right, and so came to the conclusion that I would just have to learn to live with a world without hope and meaning.

It was highly fashionable in the 1960s for social progressives to affirm and rejoice in the meaninglessness of life. It was hard for me, as an impressionable teenager, not to be swept along by this remorseless rationalism, which limited reality to what science and reason could prove, and despised those who quested for meaning in life as old-fashioned utopians, incapable of coming to terms with a scientific worldview.

Yet I came to realize that the view that science alone determines reality could not be sustained. In December 1970, I learned that I had been awarded a scholarship to study chemistry at Oxford University. I would not be taking up that place until October 1971, so decided to stay on at my high school for the remainder of that year, and use the time to learn Russian and German, and bring my scientific reading up to speed, especially in the biological sciences.

It was during this period that I began to explore the history and philosophy of science, and began to realize that the scientific positivism that I had so willingly and unthinkingly embraced was unsustainable. This did not cause me to embrace a religious faith. It did, however, do two things for me. First, it destroyed my naïve scientism – as we would now call it – which insisted that science alone could answer all of life’s important questions. And second, it made me receptive to the possibility of a wider and deeper encounter with our world, of which science was an important part – but only a part.

Things fell into place at Oxford, where I discovered Christianity and C. S. Lewis (in that order). Lewis helped me to see that Christianity created intellectual space for the natural sciences, while insisting that they were only part of a greater vision of reality. C. A. Coulson, Oxford’s professor of theoretical chemistry at this time, famously argued that Christianity and the natural sciences offered different – and potentially complementary – perspectives on reality. Perhaps more importantly, he mounted a devastating critique of a ‘God of the gaps’ approach, which located God in the scientifically inexplicable. For Coulson, Christianity offered a grand vision of reality, which explained why science was able to explain anything in the first place. Explicability itself demanded an explanation. Between them, Coulson and Lewis made me realize that my Christian faith did not displace my love of science, but framed it positively, helping me appreciate its strengths, while being alert to its limits. Science is great at helping us discover how the universe works – but it is useless when it comes to finding out what it means.

We need to bear this point in mind when reading Steven Weinberg’s famous 1977 declaration that ‘The more the universe seems comprehensible, the more it also seems pointless.’ Weinberg’s point relates to the strengths and weaknesses of the scientific method. Its great strength is that it makes our universe rationally transparent, so that we can see how it functions. Yet this same method is incapable of disclosing meaning. The outcome is inevitable: the method that enables us to understand our world cannot help us discern its purpose. We need another perspective, another method, another intellectual toolkit to make this happen. That’s where Christianity comes in.

I opened this reflection by talking about the ‘Belt of Orion’, which once spoke to me of the pointlessness of a brief human life. I still look at those stars on cold winter’s evenings. So how do I see them now? I still feel a sense of wonder at their solemn stillness. Yet Christianity gives me a new way of reading the night sky. Like the Psalmist, I find myself overwhelmed by the depth of the universe, yet consoled by the thought that, in a way I still do not fully appreciate, those stars proclaim the glory of a God who made the world, yet chose to enter it in order to redeem us (Psalms 8; 19). I see the night sky through a new lens, which allows me to discern – not impose or invent! – its true meaning and purpose, and thus to appreciate it all the more.

Alister McGrath, a former atheist, is now the Andreas Idreos Professor of Science and Religion at Oxford University. His recent books include Enriching Our Vision of Reality: Theology and the Natural Sciences in Dialogue (2016) and A Theory of Everything (That Matters) (2019).

Lewis, Narnia, and the Power of Myth

Why are C. S. Lewis’s “Chronicles of Narnia” – especially their showcase opener The Lion, the Witch, and the Wardrobe – so popular, fifty years after Lewis’s death? Many answers might be given – such as the obvious fact that they are stories well told, or the suggestion that they call us back to a lost childhood. Yet perhaps there is something deeper here.

To understand the deep appeal of Narnia, we need to appreciate the place of stories in helping us to make sense of reality, and our own place within it. The “Chronicles of Narnia” resonate strongly with the basic human intuition that our own story is part of something greater and grander—which, once we have grasped it, allows us to see our situation in a new and more meaningful way. A veil is lifted; a door is opened; a curtain is drawn aside; we are enabled to enter a new realm. Our own story is now seen to be part of a much bigger story, which both helps us understand how we fit into a greater scheme of things, and discover and value the difference we can make.

Like his Oxford friend J. R. R. Tolkien, Lewis was deeply aware of the imaginative power of “myths”—stories told to make sense of who we are, where we find ourselves, what has gone wrong with things, and what can be done about it. A “myth”, as Lewis uses the term, is not a false story told to deceive, but a story that on the one hand resonates with the deepest structures of reality, and on the other has an ability to connect up with the human imagination. Tolkien was able to use myth to saturate The Lord of the Rings with a mysterious “otherness,” a sense of mystery and magic which hints at a reality beyond that which human reason can fathom. Lewis realized that good and evil, anguish and joy can all be seen more clearly when “dipped in myth.” Through their “presentational realism,” these narratives provided a way of grasping the deeper structures of our world at both the imaginative and rational levels.

Lewis may also have come to realize the power of myth through reading G. K. Chesterton’s The Everlasting Man, with its classic distinction between “imaginary” and “imaginative,” and deft analysis of how the imagination reaches beyond the limits of reason. “Every true artist,” Chesterton argued, feels “that he is touching transcendental truths; that his images are shadows of things seen through the veil.”

For Lewis, a myth is a story which evokes awe, enchantment, and inspiration, and which conveys or embodies an imaginative expression of the deepest meanings of life—meanings that prove totally elusive in the face of any attempt to express them in purely abstract or conceptual forms. For Lewis, God authorizes the use of myth as a means of captivating the human imagination and engaging the human reason.

Lewis declares that human beings construct myths because they are meant to. They have been created by God with an innate capacity to create myths as echoes of a greater story or “story of a larger kind”. Early Christian writers spoke of the logos spermatikos, a “seed-bearing word” implanted within creation by God, preparing the ground for the definitive revelation of God in Jesus Christ. Tolkien and Lewis both (though in slightly different ways) work with the notion of mythos spermatikos, a “narrative template” embedded within the human soul as part of the created order. Once more, these prepare the ground for the definitive revelation of God in the story of Jesus Christ. This approach is not about Jungian archetypes (although they may perform a similar function); it is rather a fundamentally Christian insight about the deeper structure of reality, and the best ways of representing and experiencing it by those who bear the “image of God”.

Lewis argues that, since “God chooses to be mythopoeic,” then we in our turn must be “mythopathic” – that is to say, receptive to God’s myth, recognizing and acknowledging its “mythical radiance”, and offering it an “imaginative welcome.” And, since God uses myths as a means of communicating both truth and meaning, why should not humans do the same? Particularly those wishing to encourage their culture to offer an “imaginative embrace” to the Christian faith? Lewis offers a powerful imaginative alternative to the dull over-intellectualized apologetics of his own generation, which limited the appeal of the Christian faith to our reason.

Steeped in the riches of medieval and Renaissance literature, and with a deep understanding of how “myths” work, Lewis managed to find the right voice and the right words to get past the suspicions of a “fully waking imagination of a logical mind.” Somehow, Narnia seems to provide a deeper, brighter, more wonderful, and more meaningful world than anything we know from our own experience. Though the “Chronicles of Narnia” are clearly a work of fiction, they nevertheless seem far more “true to life” than many supposedly factual works. These evocative stories help us grasp that it is possible for the weak and foolish to have a noble calling in a dark world; that our deepest intuitions point us to the true meaning of things; that there is indeed something beautiful and wonderful at the heart of the universe; and that this may be found, embraced, and adored.

Tolkien’s Lord of the Rings is about finding a master ring, that rules the other rings—and then must be destroyed, because it is so dangerous and destructive. At the deepest level, Lewis’s “Chronicles of Narnia” are about finding a master story, that makes sense of all other stories—and then embracing it, because of its power to give meaning and value to life.

But which is the true story? Which are merely its shadows and echoes? And which are fabrications, tales spun to entrap and deceive? At an early stage in the Lion, the Witch and the Wardrobe, the four children begin to hear stories about the true origins and destiny of Narnia. Puzzled, they find they have to make decisions about what persons and what stories are to be trusted. Is Narnia really the realm of the White Witch? Or is she a usurper, whose power will be broken when two Sons of Adam and two Daughters of Eve sit on the four thrones at Cair Paravel? Is Narnia really the realm of the mysterious Aslan, whose return is expected at any time?

Gradually, one narrative emerges as supremely plausible—the story of Aslan. Each individual story of Narnia turns out to be part of this greater narrative. The Lion, the Witch and the Wardrobe hints at (and partially discloses) the “big picture,” expanded in the remainder of the Narnia series. This “grand narrative” of interlocking stories makes sense of the riddles of what the children see and experience around them. It allows the children to understand their experiences with a new clarity and depth, like a camera lens bringing a landscape into sharp focus.

Yet Lewis did not invent this Narnian narrative. He borrowed and adapted one that he already knew well, and had found to be true and trustworthy—the Christian narrative of creation, fall, redemption, and final consummation. Following his late evening conversation with Tolkien about Christianity as the “true myth” in September 1931, Lewis began to grasp the explanatory and imaginative power of an incarnational faith. Lewis came to believe in Christianity partly because of the quality of its literary visionits ability to give a faithful and realistic account of life. Lewis was thus drawn to Christianity not so much by the arguments in its favour, but by grasping its compelling vision of reality, which he could not ignore—and, as events proved, could not resist.

The Chronicles of Narnia are an imaginative re-telling of the Christian “grand narrative,” fleshed out with ideas Lewis absorbed from the Christian literary tradition. The basic theological themes that Lewis set out in Mere Christianity are transposed to their original narrative forms, allowing the deep structure of the world to be seen with clarity and brilliance. A good and beautiful creation is spoiled and ruined by a Fall, in which the creator’s power is denied and usurped. The creator then enters into the creation to break the power of the usurper, and restore things through a redemptive sacrifice. Yet even after the coming of the redeemer, the struggle against sin and evil continues, and will not be ended until the final restoration and transformation of all things. This Christian metanarrative—which early Christian writers called the “economy of salvation”—provides both a narrative framework and a theological underpinning to the multiple narratives woven together in Lewis’s Chronicles of Narnia.

In one sense, the “Chronicles of Narnia” are just a story. Yet to the initiated, they are a retelling of the greatest story of all, which no human story can ever articulate adequately. Lewis’s remarkable achievement in the “Chronicles of Narnia” is to allow his readers to inhabit this metanarrative—to get inside the story, and feel what it is like to be part of it. Mere Christianity allows us to understand Christian ideas; the Narnia stories allow us to step inside and experience the Christian story, and judge it by its ability to make sense of things, and “chime in” with our deepest intuitions about truth, beauty, and goodness. Like Lewis’s wardrobe, they throw open an imaginative gateway to discovering and embracing the “Great Story”, for which this life is but a “title page”.

Alister McGrath is Professor of Theology, Ministry and Education at King’s College London, Senior Research Fellow at Harris Manchester College, Oxford University, and President of the Oxford Centre for Christian Apologetics. His latest books, published to mark the 50th anniversary of the death of C. S. Lewis, are C. S. Lewis – A Life: Eccentric Genius, Reluctant Prophet, and The Intellectual World of C. S. Lewis.

C S Lewis A Life

ECPA 2014 Christian Book Award Winner (Non-Fiction)!
Fifty years after his death, C. S. Lewis continues to inspire and fascinate millions. His legacy remains varied and vast. He was a towering intellectual figure, a popular fiction author who inspired a global movie franchise around the world of Narnia, and an atheist-turned-Christian thinker.

In C.S. Lewis-A Life, Alister McGrath, prolific author and respected professor at King’s College of London, paints a definitive portrait of the life of C. S. Lewis. After thoroughly examining recently published Lewis correspondence, Alister challenges some of the previously held beliefs about the exact timing of Lewis’s shift from atheism to theism and then to Christianity. He paints a portrait of an eccentric thinker who became an inspiring, though reluctant, prophet for our times.

You won’t want to miss this fascinating portrait of a creative genius who inspired generations.

Return from a distant country

My Theology: The world's leading Christian thinkers explain some of the principal tenets of their theological beliefs. 'I never expected to be a Christian theologian, mainly because I never expected to be a Christian,' writes Alister McGrath. 'I assumed that scientific atheism would be my permanent intellectual homeland; in fact, it turned out to be a temporary place of exile, from which I would later return, wiser and somewhat chastened.'In this fascinating book, McGrath describes his journey into faith and his vision of Christian theology, focussing on the distinct role of historical theology; the importance of engaging the relation of science and faith; the need for theologians to engage in major public debates; and the significance of theological education.

Reformation Thought

Reformation Thought: An Introduction is a clear, engaging, and accessible introduction to the European Reformation of the sixteenth century. Written for readers with little to no knowledge of Christian theology or history, this indispensable guide surveys the ideas of the prominent thought leaders of the period, as well as its many movements, including Lutheranism, Calvinism, Anabaptism, and the Catholic and English Reformations. The text offers readers a framework to interpret the events of the Reformation in full view of the intellectual landscape and socio-political issues that fueled its development.

Based on Alister McGrath’s acclaimed lecture course at Oxford University, the fully updated fifth edition incorporates the latest academic research in historical theology. Revised and expanded chapters describe the cultural backdrop of the Reformation, discuss the Reformation’s background in late Renaissance humanism and medieval scholasticism, and distill the findings of recent scholarship, including work on the history of the Christian doctrine of justification. A wealth of pedagogical features-including illustrations, updated bibliographies, a glossary, a chronology of political and historical ideas, and several appendices-supplement McGrath’s clear explanations.

Written by a world-renowned theologian, Reformation Thought: An Introduction, Fifth Edition upholds its reputation as the ideal resource for university and seminary courses on Reformation thought and the widespread change it inspired in Christian belief and practice.

Science and Religion: A New Introduction

The leading introductory textbook on the study of religion and the natural sciences, including new coverage of the latest topics in the field

Science and Religion provides students with a thorough introduction to the major themes and landmark debates in the interaction of science and religion. Incorporating history, philosophy, the natural sciences, and theology, this popular textbook examines how science and religion approach central questions and discusses the relationship between the two areas through the centuries. The authoritative and accessible chapters are designed for readers with minimal knowledge of science or theology.

Written by one of the world's leading authorities on the study of religion and science, this fully revised and updated third edition addresses contemporary topics and reflects the latest conceptual developments in the field. New and expanded chapters and case studies discuss Scientism, evolutionary theodicy, the Theory of Relativity, warranted belief in science and religion, the influence of science and religion on human values, and more. The most up-to-date introduction to this exciting and rapidly growing field, this textbook:

  • Offers an engaging, thematically-based approach to the subject
  • Provides historical context for major events in science and religion
  • Explores scientific and religious perspectives on Creation and the existence of God
  • Discusses models, analogies, and issues at the intersection of science and religion
  • Is supported by a series of videos that complement each chapter

One of the most respected and widely adopted textbooks in the field, Science and Religion: A New Introduction, 3rd Edition is an ideal resource for college, seminary, and university students in courses in science and religion; church or community courses in the relation of science and faith; and general readers looking for an inclusive overview of the field.

Christian Theology An Introduction

Christian Theology An Introdution

Christian Theology: An Introduction, one of the most internationally-acclaimed Christian theology textbooks in use, has been completely rewritten for the 6th edition. It now features new and extended material and companion resources, ensuring it retains its reputation as the ideal introduction for students.

  • A new edition of the bestselling Christian theology textbook to celebrate its 25th anniversary
  • Rewritten throughout for exceptional clarity and accessibility, and adds substantial new material on the Holy Spirit
  • Features increased coverage of postcolonial theology, and feminist theology, and prodigious development of world theology
  • Increases the focus on contemporary theology to complement the excellent coverage of historical material
  • A new 2-color design includes more pedagogical features including text boxes and sidebars to aid learning

The Christian Theology Reader

Regarded as the leading text in Christian theology for the last 25 years, Alister E. McGrath's TheChristian Theology Reader is now available in a new 5th edition featuring completely revised and updated content.

  • Brings together more than 350 readings from over 200 sources that chart 2,000 years of Christian history
  • Situates each reading within the appropriate historical and theological context with its own introduction, commentary, and study questions
  • Includes new readings on world Christianity and feminist, liberation, and postcolonial theologies, as well as more selections by female theologians and theologians from the developing world
  • Contains additional pedagogical features, such as new discussion questions and case studies, and a robust website with new videos by the author to aid student learning
  • Designed to function as a stand-alone volume, or as a companion to Christian Theology: An Introduction, 6 th edition, for a complete overview of the subject