I think the first axiom of Christianity is also the last axiom of Christianity: Jesus of Nazareth is the Christ. This is a broad statement, but one which is the starting place for Christianity. It's the place to begin for Christianity because Christ is the defining signifier of Christianity. Christ defines Christianity. Also, Christ is tangible and revealed. Prior to Christ, God was not revealed, but a wholly transcendent being who becomes man writ large; like a magnifying mirror, enlarging the virtues of the observer. This is the kind of God that looks like an Israelite to the Israelites, that looks like an Aztec to the Aztecs, etc. Little wonder thatn Feuerbach wrote, "theology is anthropology."
With Christ, however, is a revelation that transcends particularity, rather than transcending materiality. Christ is material, a human being of flesh and blood. And Christ is particular, a male Jew. But Christ is not restricted to male Jews. It is the Christ-ness of Jesus which enables this transcendence over the particularity of Jesus. It is the declaration that Jesus is the Christ that defines Christianity.
So what do we mean by Christ? And what does it mean to say that Jesus is the Christ? Christ is the revealed, tangible God. To look at Christ is to look at God. I think there are two ways to read this. First, and I think this is the more common approach, is to take the attributes of God and to say that Christ has those attributes. So we take the properties of omnipresence, omnipotence, and so on, and then say that Christ has those properties. In doing this we are exposed to Feuerbach's critique. We define God in terms that are magnifications of our own virtues, and then we say that Jesus is like that. Jesus soon starts to look like the perfect man (strong, handsome, wise, and so on).
The second way to read it is to say that what is seen in Christ is the definition of God. God is defined by Christ, not the other way around, because Christ is seen and God is not. The properties and characteristics of Christ are foundational for his followers, and also for God. In the paraphrased words of a friend of mine, "If it looks like Christ, then it's of God." And therefore, if it doesn't look like Christ, it's not God and probably the result of some human imagining. This approach takes away some of the speculation associated with theology, with the discussion of a transcendent being. Placing Christ at the centre of faith, and of the life of faith, is a defining move. The world, and everything in it, is now defined in relation to Christ and not in relation to the observer.
And this is the point of this axiom. In taking Christ as the first and the last, we de-centre our lives. Rather than building up a phenomenology of conscious experience or idealism, we start with the assertion that Jesus is the Christ and begin to work outwards from there, applying it to the way we read the Bible, the things we believe about God, and the way we live. The Christian life of faith is not founded on empirical evidence about Jesus but on this axiom. Christ is the first and the last, the foundation of Christian faith.
1. That's not, however, the same as there being evidence or argument to disprove it. It's possible for an axiom to be self-contradictory, or for some other evidence to disprove it. But it's also possible to conceive of an axiom with is neither provable nor disprovable (e.g., concerning the existence of God).
2. This is the Jesus that looks like a surfer carpenter. Just because Jesus was a tradesman who associated with fishermen, it doesn't mean that Jesus was the local pinup boy, tanned and muscular. Take a good look at tradesmen from peasant cultures sometime and see what I mean.
3. I wonder whether Christian writing should therefore be only Christology, and not lumped together as theology.
4. You can recycle or burn your apologetics books now.