There are dozens of reasons why I am Christian, but here are 7 of them:
1. Jesus is God - This is the Christian claim and what I truly believe with ALL my heart.
2. My Environment - While the people and experiences in my life do impact my beliefs, I am not Christian simply as a result of my environment. While environment does not play a major factor in my faith, I didn't want to ignore this point since it always plays some role.
3. Jesus Claimed to be God - This fact can't be ignored. ALL of us must have a response to this point and there are really only 3 logical approaches to this claim (according to C.S. Lewis): Either He is a Lunatic, a Liar, or He really is the Lord (who He claims to be).
4. The Evidence Supports Jesus' Claims - The evidence certainly points to the Him being Lord: 100s of Prophecies fulfilled, miracles performed, witness of His followers, His teaching and wisdom, the amazing History of Christianity, etc.)
5. Grace - While reason and logic point to Christianity; ultimately I am Christian because of the Grace of God - His free gift of faith that I have been receptive to.
6. Christianity is Practical - Christianity Work! It satisfies the deepest desires of our hearts.
7. I Know Jesus - Jesus is not only a historical figure, prophet and miracle worker; Jesus is ALIVE today and lives in you and He lives in me. I know Him. I talk to Him everyday and have a personal relationship with Him. I know He loves me and I love Him.