First I would express great sorry, for the way we men and women have screwed the world up, "shameful things in his Name." Then two, I would ask him, "How he would have done it differently."
Since he would not recognize the world, all the big churches that have been build in his name, the wars that have been fought, between Christian enemies and the Christians, we would have a lot to talk about.
Things like, "What is a Christian?" Jesus wouldn't recognize what we are doing in his name.