That certainly is the big question: What is Christianity for? Rod Dreher at CrunchyCon poses this, in an essay I would commend for your reading. My comment is below.
As a former Roman Catholic (is there really such a thing?), now attending a Baptist church, I thought I knew the answer. The school solution, as we used to say, is this: Christianity’s purpose is to bring us to eternal life with God the Father through his son, Jesus.
Simple answer; explains very little beyond what the reader already believes to be true about salvation. For example, do we need a priest to mediate between ourselves and God? Wasn’t that precisely the role that Jesus took upon himself, as the sole mediator for our conversations with God?
Do we need sacraments; do we need to be baptized in any particular manner; do we even need to be baptized at all, if we are going to ignore other things that Scripture instructs us to do?
As a Catholic, I feared God; feared the judgment that the Bible promised was to be rendered by Jesus. And I use “fear” in the sense of awe and reverence. This fear inspired two things: right living, or at least an attempt at it. And guilt when, inevitably, we fall short of living a Christian life.
As a Protestant, I hear people treat Jesus as though he were some sort of celestial butler; “what a friend we have in Jesus…” as the song goes. Jesus, although fully God in the Trinity, somehow comes down to make sure we eat our vegetables, and a host of other trivial things. Jesus makes sure we win our hockey and football games, although such games are played against equally worthy (or equally sinful if you’re a cup-half-empty guy, i.e. Catholic).
Yes, God knows all. But salvation history includes a lot of things we must, in honesty, call evil, or, at least, no so good. Catholic or Protestant, there are two overly-simplified answers I can give to those who question the basic goodness of God in the face of evil: first, that evil in this world is a product of our sinful natures; a natural by-product of the Fall.
Second, there is the true but useless statement, “God works in mysterious ways.” Translation: bad things happen all the time, but God must have some purpose that we just don’t grasp as yet. Perhaps; but this is not an answer. It’s an excuse.
So, what to do in the here and now? Prayer is always good; who knows, you may get an answer from the Big Guy. Your surely will not get an answer if you don’t first ask.