Clive Staples Lewis was born on November 29, 1898 in Belfast, Northern Ireland. His mother, Flora Augusta Hamilton Lewis, died when he was young, leaving his father, Albert, to raise him and his older brother Warren, known as Warnie. Warnie and Jack, as Clive preferred to be called, grew closer as they got older. Simultaneously, the brothers grew apart from their father, whose boisterous sense of humor and awkward good nature did not match their reticence. The boys immersed themselves in a game of "Animal Land and India." Jack was obsessed with talking animals and Warnie was intrigued by the land of India, so they mapped out a place called Animal Land which bordered on India. Animal Land had talking animals that were frequently engaged in trade and commerce with the Indian people. Many people have seen Animal Land as a precursor to the land of Narnia, but those who have actually read the stories Jack wrote about Animal Land say they show very little of the imagination and wit Jack infuses into the Narnia Chronicles. In short, they are boring. Nevertheless, the idea of a fantasy land populated with talking animals certainly started with Animal Land.

C. S. Lewis had a terrible time in grammar and early high school. He was completely unathletic, which was a major liability given the focus on sports in the schools which he attended. Lewis was a victim of a system called "fagging" in which the older, stronger boys at the school were not only permitted, but encouraged, to boss around the younger ones. This loathing of school life surfaces in many of his books, particularly in The Chronicles of Narnia, which includes the book, The Lion, the Witch, and the Wardrobe. For example, the character Professor Kirke bemoans the state of modern education, Edmund becomes a misfit when he begins to attend school, and later, in The Silver Chair, Jill Pole and Eustace Scrubb attend a terrible school that seems to be modeled closely on Lewis's own experience. Lewis escaped this torment as soon as he could, studying instead under a private tutor named Mr. Kirkpatrick. He thrived under the challenge and stimulation of learning under this singular teacher's tutelage.

Lewis was born and raised Protestant, but his faith gradually became less tangible to him as the years progressed. It is unclear when he crossed the line from lackadaisical believer and agnostic, and still harder to know when he went from agnostic to atheist, but by the time he began to attend University College in Oxford, Lewis was a non-believer. Soon after beginning his college studies in 1917, Lewis was drafted into the army, and went reluctantly but determinedly to war. He was wounded on April 15, 1917 during the Battle of Arras, and though he returned to service in October, he was discharged soon after. He resumed his college studies and his life over the next ten years was quiet, except for a possible, unconfirmed love affair with Mrs. Moore. During these years he made a slow, steady return to a belief in Christianity. He often experienced an indefinable sensation that he named "joy," a sort of spiritual longing that seemed to bear little relation to any physical or spiritual pleasure or indulgence with which he was acquainted. These flashes of joy grew more frequent and were compounded with a troublesome sense that Christianity actually made a good deal of sense. Lewis resisted conversion fiercely, but he eventually realized that it was no coincidence that all his favorite writers were Christian and that their works carried an unmistakable hint of spirituality and Christianity. In 1929, he converted back to Christianity, though very reluctantly.

Once Lewis was convinced of the validity of Christianity, he was in an excellent position to convince others. His painstaking struggle with the logic behind faith left him well equipped to argue with others about faith. It is not an exaggeration to say that there is no well-known book by Lewis that does not prominently feature the theme of Christianity. Some of his works were apologetics, in which he argued for Christianity from an intellectual standpoint. Other books straddled the line between commentary and fiction, such as The Screwtape Letters, which was a series of letters from an experienced devil advising his young, inexperienced nephew on the best ways to corrupt the soul of the human to whom he has been assigned as guardian devil. Some of Lewis's books are fiction, like The Chronicles of Narnia, The Space Trilogy, a series of science fiction novels, and Till We Have Faces. Still others are intensely personal, such as Lewis's autobiography, Surprised By Joy, and his reflections on the death of his wife, A Grief Observed. Through most of his life, Lewis maintained a very intellectual perspective on his faith and on his life in general. He was a bachelor most of his life, and his estranged relationship with his father had possibly made him wary of deep affection or love. Lewis's ability to think logically through his faith was flawless, but there is an emotional understanding of religion that seems to be lacking from his work. Its lack is unobtrusive, but not unnoticeable.

In 1952, while Lewis was immersed in writing The Chronicles of Narnia, Lewis met Joy Davidman Gresham. Joy was a plain-spoken American woman fifteen years his junior with whom he became acquainted originally through a fan letter and a chance meeting. The two became friends as she struggled with a difficult marriage. She eventually divorced her husband in 1953 on grounds of desertion. Their friendship grew, but it remained no more than friendship, even after they were married in 1956. The marriage was arranged to avoid Joy's deportation from Britain, so although they lived in the same house, their relationship was limited to chaste affection. Slowly they fell in love, and when Joy was diagnosed with bone cancer later in 1956, Lewis realized that he loved her and they were married at her bedside in the hospital. Her death seemed imminent, but she had a near-miraculous recovery during 1957, and the two of them lived together blissfully for three more years, evoking in Lewis a passion for Joy and life that he had never known. The novel, which he considered to be his best work, Till We Have Faces, was written with Joy in mind in the role of the female protagonist. In 1960, Joy's cancer returned, and this time there was no miraculous recovery. She died that year at the age of forty-five, and Lewis deeply affected by her death after their brief period of happiness. To work through his grief and to cling to his faith, Lewis kept a journal of his reactions, which he later published under the pseudonym N. W. Clerk and under the title of A Grief Observed. This work represents one of his first attempts to reconcile his intellectual belief in Christ with the shattering experience of losing his wife in real life. The previous separation between his mind and his emotions in regard to faith was destroyed, and A Grief Observed is evidence of his frantic struggle to come to terms with an understanding of faith on an emotional level. Lewis achieved this, although he was possibly a permanently heartbroken man. He died on November 22, 1963, of a variety of illnesses, most notably a heart attack and kidney problems.