Why am I a Christian?

A brief excerpt from a personal letter that I wrote in January; I thought it might be relevant to whomever reads this blog:

"So, “Why do I believe in Christianity?” huh?... When I was a child, I simply believed and accepted that the Bible was the only basic truth in life. I acknowledged and embraced it intellectually, even defending it to my friends through my teenage years, but now, looking back on my “fruits” during those years, I'm not sure if I was ever saved until college. If I was saved, I was a baby Christian, not understanding Christianity fully and not letting it affect my life as it should have.

Anyway, I think my answer to your question can be broken down to three levels: spiritual, intellectual, and practical/moral. First, I believe, because God gave me faith. (This is the foremost reason; the other two follow from this one.) He gave me the ability to understand and believe that I am a sinner who deserves death, that Jesus paid the penalty for my sins, and that He was resurrected on my behalf so that I can have eternal life. Second, because Christianity offers the best intellectual framework in which I can understand this world, including myself. I struggled much to come to this conclusion during my college days; I had “times of doubt,” if you will. Still, I am not yet aware of any other philosophy that explains human condition as well as Christianity. Thirdly, because in Christian understanding, everything in my life/in the world finds its fullest expression and meaning! In other words, living by the Bible (which I see as God's law) has real, tangible benefits in this world. I have seen this in my parents' lives when I was younger, and now I see it in my life and other Christians' lives."

Why are you a Christian? Or, why not?