Space Jesus? That's just silly.
I always thought when the Engineer was touching David, he figured he was an android, thus enraging him because their own creations dared to create their own little image as well. Maybe he should have touched Weyland first, and everything could have turned out more...civilized. But hey, where would that leave Prometheus 2 then? I think neither Ridley, nor Lindelof or Spaiths really knew exactly how this whole thing was supposed to unravel. The movie wasn't really so much about plot cohesion, but about making people wonder what's next and why and this and that. Okay, mission succesful. The next screenwriter certainly has a lot of holes and answers to fill though.