J. R. R. Tolkien
The request for a sequel prompted Tolkien to begin what would become his most famous work: the epic novel "The Lord of the Rings" (originally published in three volumes 1954–1955). Tolkien spent more than ten years writing the primary narrative and appendices for "The Lord of the Rings", during which time he received the constant support of the Inklings, in particular his closest friend C. S. Lewis, the author of "The Chronicles of Narnia". Both "The Hobbit" and "The Lord of the Rings" are set against the background of "The Silmarillion", but in a time long after it.
C. S. Lewis
Lewis's interest in the works of George MacDonald was part of what turned him from atheism. This can be seen particularly well through this passage in Lewis's "The Great Divorce", chapter nine, when the semi-autobiographical main character meets MacDonald in Heaven:
He eventually returned to Christianity, having been influenced by arguments with his Oxford colleague and Christian friend J. R. R. Tolkien, whom he seems to have met for the first time on 11 May 1926, and the book "The Everlasting Man" by G. K. Chesterton. Lewis vigorously resisted conversion, noting that he was brought into Christianity like a prodigal, "kicking, struggling, resentful, and darting his eyes in every direction for a chance to escape". He described his last struggle in "Surprised by Joy":