Mere Christianity should be on every LDS bookshelf.
As for his thoughts on complexity vs simplicity, one has to look at Lewis' life. He started as an atheist, and became a Christian later in his adult life. He saw that atheism was too easy a way to explain life, but it answered nothing. To disbelieve what one does not see, does not explain the world around us. Nor does it explain the feelings of peace and joy one feels as a believer. Occam's Razor does not mean one accepts the simplest answer/reason, but the simplest one that explains all things well. Atheism and science do not explain First creation, or the "why?" to existence. Why was life formed on this world, and then develop into intelligence beings that could relate, imagine, and even ponder about the concept of God.
Interestingly, some of his writings make traditional Christians uncomfortable, while LDS are very comfortable with most of what he wrote about.
Rameumptom: A Holy Stand or Podium, where I can pontificate to my heart's delight.