Christianity tends to be defined as a series of abstract doctrinal statements to which one may or may not give assent. I think this is an expression of the modern preference for abstract thought and individualism over culture.
When one actually sits down to read the Gospels one finds that Jesus does not propose a series of doctrinal theses that one must believe. Instead he spends quite a lot of time speaking about the Kingdom of Heaven. The Kingdom of Heaven in Jesus’ language is not the place where we go when we die assuming we believed in the proper doctrinal statements; he mentions the afterlife, but surprisingly little.
The Kingdom of Heaven is the space where God is King. The hope of Israel was partly political – freedom from Roman rule – but it was also much more spiritual than we moderns tend to give it credit. Ancient peoples did not divide politics, religion and spirituality the way we do. The hope was that God himself would rule Israel, and God himself would set the world aright. That he would make this fallen world the space where his will would be obeyed. The Kingdom of Heaven exists wherever people live as God wants them to live.
And like any Kingdom, this one is a community.
Jesus very intentionally set about creating a community: he was not only traveling with a core group of followers and building up a network of friends, disciples and benefactors, he was establishing a “new Israel”. The best example was his setting up the twelve and granting them authority: to any first century Jewish observer the allusion to the twelve sons of Israel – legendary founders of the twelve tribes – is obvious. The community is the space where God is obeyed. I do not think Jesus’ rich Kingdom imagery refers only to the community he founded, as if that exhausted the concept of ‘the Kingdom’, but the two were clearly connected in his mind.
If you ask a Catholic from, say, the 19th century “Why did Jesus come?” you would get the answer “To found the Church” which sounds like an awful bit of triumphalism (and it is) but understood correctly it is not wrong, just limited. No, Jesus did not intend to found the Avignon Papacy or the Holy Inquisition. If Petrine Primacy is to be attributed to Jesus (and Matthew says it is), he could not not have imagined the forms it would take, nor its abuses. But Jesus did intend to found a community which soon took to calling itself the church.
That community has it’s traditions, its way of looking at the world, its internal polarities and debates. It is a culture. The community, despite shortcomings that the whole world can see, is what Jesus of Nazareth imagined and willed into existence.
Another reason it is difficult to imagine Christianity as a culture, or as community, is because only a few decades ago the Western world was deeply influenced by Christian culture. It was hard to see something when it was so big. That is no longer the case as the contradictions between Christian culture and modern culture, the cracks papered over for so long, have lately been widening and are becoming unbridgeable. The experience of Christians in the West will little by little resemble the situation of Christians in the ancient world, or in the modern East, or the Amish in America, or the ghetto life of Jews down the ages: that is, of a conspicuous, somewhat insular minority, appreciated by some, held under suspicion by others. Then the communal nature of Christianity will be obvious. In such a situation, it might become the chief attribute.
Nowadays you cannot be a good Christian without community. The days are coming when you cannot be a Christian at all without community.