Here's something to ponder:
I don't mean to be anti-theology here. It just seems thought-provoking, that's all.
Theologians have felt no hesitation in founding a system of speculative thought on the teachings of Jesus; and yet Jesus was never an inhabitant of the realm of speculative thought.
By the way, if you don't already know about Walter Rauschendbusch, I recommend that you click through and read up on him. Very interesting and compelling figure.