the most unbelievable aspect of Christianity is the fact that God gave up his only son for me, you, everyone. It's hard to take that on board as a human being, hard to understand God's amazing grace, so great that he sent us a Saviour. It's unbelievable - but not in a way that says "That's a load of crap, I don't buy it", rather in a way that says "Whow, it's so hard to believe that God would do that for me, for a simple human being, that he would show that much grace and love. It's unbelievable, but I gotta believe."