Philosophy! It's Everywhere!

I was at church today and my pastor told everyone at the end of his sermon that we had homework. Our homework was to think about why we are Christian. Immediately, I attempted to decipher why I am a Christian and I could not find my answer in a matter of seconds. Is it because this is what I know? I was raised to be Christian? Am I Christian? I just started thinking, then going back, I remembered Philosophy class in the first week or so, and decided to share this on the blog. But in all honesty, why do we believe what we believe?