In this collection, I noted the Christian reading list in this letter excerpt (page 345):
The first real work of the Gospels on a fresh reader is, and ought to be, to raise very acutely the question, “Who or What is this?” For there is a good deal in the character which, unless He really is what He says He is, is not loveable or even tolerable. If He is, then of course it is another matter: nor will it then be surprising if much remains puzzling to the end. For if there is anything in Christianity, we are now approaching something that will never be fully comprehensible.
On this whole aspect of the subject I should go on … to Chesterton’s Everlasting Man. You might also find Mauriac’s Vie de Jesus useful … If childish associations are too intrusive, in reading the New Testament it’s a good idea to try it in some other language, or Moffats’s translation.
As for theology proper: a good many misunderstandings are cleared away by Edwyn Bevan’s Symbolism and Belief. A book of composite authorship and of varying merit, but on the whole good, is Essays Catholic and Critical ed. E. G. Selwyn (S. P. C. K.). Gore’s The Philosophy of the Good Life (Everyman) is rather wordy, but taught me a lot. If you can stand serious faults of style (and if you can get them, they are long out of print) Geo. Macdonald’s 3 vols of Unspoken Sermons goes to the very heart of the matter. I think you would also find it most illuminating to reread now many things you once read in “Eng. Lit” without knowing their real importance — Herbert, Traherne, Religio Medici.
As for a person “with whom to discuss,” choice is more ticklish. L. W. Grensted is very interested in psychoanalysis and wrote a book on its relation to Christianity: would that be an advantage or the reverse? O. C. Quick whom I know and like. Milford, the present rector of St Mary’s, some like and some don’t. Let me know what, or what sort you want, and I’ll see what can be done.
Come see me when you’re better and bring the gudeman.
I noted another Christian reading list on page 477. And Lewis says on page 501 that he likes Thomas Merton’s No Man Is an Island, and on page 340 that he doesn’t like Karl Barth. (Speaking of Lewis’s reading lists, there’s also one in The Joyful Christian, a compendium of 127 readings by him from various sources; the one there is headed, “Spiritual Reading,” and it’s found on pages 102-04. It begins with Lewis warning that old, tried and true readings (the Bible itself, of course, and Augustine, Aquinas, Hooker, and Butler, to list his examples) should be favored over the new. The list that follows is similar to what I just quoted, with these additions: (a) for popular apologetics, Charles Williams’s He Came Down from Heaven (“doesn’t suit everyone, but try it”); for “meditative and devotional reading,” The Imitation of Christ (“astringent”), Traherne’s Centuries of Meditation (“joyous”), and Lewis’s own George Macdonald: An Anthology; (c) for Christian morals, Smoke on the Mountain (by Joy Davidman, Lewis’s wife), Gore’s The Sermon on the Mount, and William Law’s Serious Call to a Devout and Holy Life (“possibly (but with a grain of salt, for he is too puritanical)”); (d) as “mouthwash for the imagination” (emphasis in original), Mauriac’s novels, Dorothy Sayers’s Man Born To Be King (“those broadcast plays”), Charles Williams’s fantastic novels, and Pilgrim’s Progress (“if you ignore some straw-splitting dialogues on Calvinist theology and concentrate on the story, [which] is first-class”); (d) Augustine’s Confessions; (e) George Herbert’s poetry; and (f) “As regards [Lewis’s] own books, you might (or might not) care for Transposition, The Great Divorce, or The Four Loves.” Finally, “[a]bout prides, superiorities, and affronts, there’s no book better than [again] Law’s Serious Call to a Devout and Holy Life ….”)
Back to this collection of Lewis’s letters: He notes on page 354 that it is providential that Hebraic poetry remains poetry when translated.
On page 355, Lewis describes the day he got the idea for The Screwtape Letters, and on page 372 is his amusing response to the “Society for the Prevention of Progress” (he accepts their offer of membership).
Note: Lewis’s father died in late 1929; the very next letter not about his death is to Owen Barfield and mentions God/belief; Lewis’s re-conversion is in 1931, a few months after his brother’s reconversion, according to another source. So, did their dad’s death help do it? Well, I read (or re-read) later that Lewis himself denies this in Surprised by Joy.