"A Course In Miracles" (and that's a lengthy read...)

Also "Everyday Grace" by Marianne Williamson.

Recently finished: "The Disappearance of the Universe" by Gary Renard. It's a marvelous book. Also, "Many Lives, Many Masters", which has to do with a psychiatrist's investigation of the possibilities of reincarnation...via one of his patients. Another very good book.

They're all essentially about the same thing: spiritual evolution and the development of higher consciousness.