What is Christianity? How do you explain what Christianity is to an unbeliever? Some say it is a philosophy, others say it is an ethical stance, while still others claim it is actually an experience. None of these things really gets to the heart of the matter, however. Each is something a Christian has, but not one of them serves as a definition of what a Christian is. Christianity has at its core a transaction between a person and God. A person who becomes a Christian moves from knowing about God distantly to knowing about him directly and intimately. Christianity is knowing God.
by Timothy Keller
Source: www.redeemercitytocity.com