Interesting topic. I am one of the few here to have voted yes, so let me explain my reasoning here.
To be a Christian means to follow the teachings of Christ. Some of you say that it is also necessary to believe he is the son of God, but that is a bit difficult if you don't believe in God. And I don't think that's necessary at all. I think the most important part of Jesus's teachings wasn't "believe in God," it was "be a good person," and you can do that without believing in God. And if I remember correctly, in some of the early, non-canon gospels, Jesus was, in fact, not considered to be the son of God, but I don't have a source on that.
There have been various schisms within Christianity, and there are many different variations of it based on different interpretations of the Bible. Many supernatural events are often taken to be allegorical, for example, the creation of Earth. Taking God as an allegory for an ideal is just one step further.
I do not consider myself a Christian, by the way.