Because it often tends to turn into a threadjack, several have requested that I start a thread explaining what I mean by Christianity, so that the matter can be discussed without distracting from the main substance of the thread.
Essentially, my belief is that Paul and his followers corrupted the message of the Christ (manifested, but only imperfectly, in the person of Jesus). For whatever reason (Tolstoy offers a plausible and sympathetic explanation in The Gospel in Brief), they chose to emphasize the constructed myth of the divinity of Jesus's person over the truth of the divinity (in a non-theistic sense, such as we might say "this chocolate is divine!" though obviously with much more import) of the Christ's teachings, as transmitted (sometimes with errors) through the life and person of Jesus.
So the Christ is merely an abstraction, an ideal human being that serves as an example for all of us in living our own lives. Jesus came very close to this ideal--though not perfectly, as we shall see--and is the originator of the particular tradition (however corrupted it may have been by the Paulinists) in which I learned the teachings that will help me reach this ideal. Other traditions exist and are of course equally legitimate.
Now, the Christ is the example we should follow because it is the means by which we will be saved from destroying ourselves. The Christ shows us how to build a better world and live among one another peacefully and happily. Thus, any beliefs which conflict with this goal are literally incompatible with Christianity. Since there is in fact no god, supplication to a deity can do nothing towards building a better world--and it is a distraction from work that will actually have an effect. Thus, belief in a god is incompatible with being Christ-like; so atheism is not a part of Christianity. Of course, individual Christians may still fall short in this are as they do (myself included) in other areas. But ultimately, atheism is something a Christian should strive to embrace just like he should strive (whether or not he necessarily actually succeeds) to embrace the other attributes of Christness.
Now, it's pretty clear that Jesus was a theist. This is but one example of what I mean when I say that Jesus was only an imperfect manifestation of the Christ. He had his flaws, as do the rest of us. Jesus's imperfection indeed is one of the thing that makes him such a compelling teacher. Even if his imperfections aren't necessarily the same as my imperfections, I can certainly relate to the basic fact of being imperfect.
The Epistles are not part of Christianity because they are written under the presumption that the divinity is found in the person rather than in the teaching. Similarly, the Old Testament is not relevant to Christianity because it is simply the national mythology of the Hebrew people. It provides cultural context for understanding Jesus's specific actions, but it has no universal significance in and of itself. Finding Christianity requires focusing solely on the Gospels, edited to (a) remove the parts that are clearly physically impossible (e.g. the miracles) and (b) removing the parts where Jesus was not being the Christ.
I'm glad to answer whatever questions you may have. You might even ask a question that forces me to reconsider some things (others have in the past), or even everything.
