How God Became King

Ever since I was a teenager, I've been obsessed with a question: Why did Jesus live? What, in other words, about everything that happened between the stable and the cross?

There were, after all, Christmas carols and other hymns that took Jesus straight "from his poor manger to his bitter cross." Did it matter that, according to the four gospels, he had a short period of intense and exciting public activity at the latter end of his life? What truth could we learn from it? Why did it have to be like that? Does it matter that he did all those things, that he said all those things, that he was all those things? Would it have made any difference if, as the virgin-born son of God, he had been plucked from total obscurity and crucified, dying for our sins, without any of that happening? If not, why not?