One of my favorite resources for learning about the Apostasy and the Restoration is Mormonism and Early Christianity by Barry R. Bickmore. His site contains many well-documented essays demonstrating that key parts of LDS theology are closer to early Christianity than to modern mainstream Christianity, consistent with the LDS concept of a Restoration. Many of the LDS concepts that lead our critics to exclude us from what they call “historic Christianity” were also early Christian concepts.
One of many interesting pages on Barry’s site is “The Nature of the Spirit World,” which shows that Joseph Smith’s teachings about the spirit world were quite out of place in his day but share many elements with early Christian teachings.
I am especially happy to remind that Barry’s monumental book, Restoring the Ancient Church: Joseph Smith and Early Christianity (Ben Lomond, CA: The Foundation for Apologetic Information and Research, 1999), is available online at FAIRLDS.org for free! This one is worth studying. How kind of Barry and FAIRLDS.org to make it available to the world at no cost.
Inspired by Barry’s essays, a few years ago I purchased and devoured The Apostolic Fathers and also spent a lot of time reading through online documents of early Christian writers. I relied on these sources for part of my essay on faith, grace, works, and salvation. I was intrigued at how many of the earliest Christian writings sound so much like typical LDS sermons at, say, General Conference, and very unlike modern preaching on salvation by faith alone without works or free agency. (That point is open for debate, of course – I would be interested in hearing other views based on the evidence from the The Apostolic Fathers, for example.)
I’ve just added Barry’s book and his Early Christianity site to my permanent “Other Links” list at the right. I hope you’ll explore both works.