I just read a fantastic book called Why I Believed: Reflections of a Former Missionary by Kenneth Daniels. You can read it for free here at Internet Infidels. Ken tells a very touching story, and also manages to respond to a lot of Christian arguments with good sense and reason. Here's a quote that really struck a chord with me:
"In the end I realized it is human judgment alone that comes to the conclusion that the Bible is God-breathed. When skeptics challenge the Christian faith, they are merely pitting one fallible human perspective against another. There is no more to it than that. Did God tap ever me on the shoulder to tell me he wrote the Bible? No, and even if he had, how would I have known it was God? Ultimately I had to fall back on human judgment to make that determination. This debate is not one between skeptics and God; it is one between fallible skeptics and fallible believers. When my high school Mormon friend learned of my deconversion, he admonished me not to lean on "the arm of flesh" (Book of Mormon, 2 Nephi 4:34) or human reason, but to listen to God. Yet we must all use our human reason or intuition or tradition to decide where we think God's voice can be found (if it is to be found at all), whether in the Jewish scriptures, in the Protestant Bible, in the Catholic Bible, in the Koran, in the Upanishads, in the Book of Mormon, in other sacred texts, in nature, or in our own heads. There is no way out of this bootstrapping problem other than to make a human judgment at some level."