Lewis knew that many of the undergraduates might have to go to war, as he had, before they finished their studies at Oxford. In this sermon, he attempted to answer the question, "What is the use of beginning a task which we have so little chance of finishing?" As was typical in his sermons, he went straight to the heart of the matter, which dealt with the "ordinary" life of the Christian. He stressed the point of doing everything to the glory of God. The Christian must serve and obey God despite world crises, problems and anxieties. For Lewis, the Christian always lived "on the edge," since all were going to die sometime. He made clear the idea that God sees all service done in His name as spiritual, regardless of how humble or exalted the person is.

"The Weight of Glory" is considered by many as the greatest and most eloquent sermon Lewis ever preached, and one of the finest ever preached by anyone. Its beauty, "friendly scholarship," and effortless delivery made it memorable for many who heard it, according to witnesses. It was delivered at St. Mary's at Evensong on June 8, 1941, to one of the largest audiences ever assembled there in modern times. The great hall was so packed that some students could only find room by sitting in the windows. His textual basis for the sermon was 2 Corinthians 4:16-18: "For we do not lose heart ... For this slight momentary affliction is preparing us for an eternal weight of glory beyond all measure ..."

Lewis' focus for the sermon was Heaven, something he said he wrote about in nearly all his books. In a serious tone, but with a cheerful appearance, he warned his listeners not to heed "worldly philosophies" (like progressive evolution) that led people to believe that this world was their true destiny, their real home. He spoke of the spiritual longings of humankind, and paid special attention to "the desire which no natural happiness can satisfy," which he called "joy." This was the same desire for God that he had written about so movingly in his spiritual autobiography, Surprised By Joy.

Near the end of the sermon, Lewis reminded his hearers not to forget that Heaven starts on this earth, and it starts with Christian love and charity towards one's immediate neighbors. These people are holy because they are God's creations and because Christ died for them and was in them. He stated emphatically that God did not create ordinary people; that everyone, no matter how beautiful or horrible, is immortal in some way.

"Transposition" was preached in the chapel of Mansfield College, Oxford, on the Feast of Pentecost, May 28, 1944. The day after, a local newspaper, The Daily Telegraph, called Lewis "Modern Oxford's Newman." It was reported that Lewis was so overcome by emotion that he stopped in the middle of the sermon, said "I'm sorry," and left the pulpit. After receiving assistance, and after a hymn was sung, Lewis returned and finished the sermon with his deeply personal feelings about his subject (and its setting) still evident.