So, your question is, if I understand it correctly, "what would Christianity (New Jerusalem Church as you put it) be today without the writings and epistles of Paul?"

First, let me voice a personal belief:
I firmly believe that following the death of the Apostles and Prophets who had been called to lead Christ's church, there was a falling away from truth. In other words, there was an apostasy among what was know as the Christian church, and that what resulted was many different variations of "Christianity." Now, this came about not because the teachings weren't true (I.E. Paul's teachings) but because men were interpreting them without divine assistance. (I.E. Prophets and Apostles) I believe that this is what is meant in the prophecy in Amos 8:11-12.

Please keep in mind that the above statement is for clarity sake, and is not open for argument. If you wish to discuss it, please start another thread or PM me.

So to answer your question of "What would Christianity be without Paul" I say that it would largly be the same, in that the beliefs of most Christian churches would still be the doctrines of men (Matthew 15:9). Now I say that advisably, noting that I also have a firm belief that Chirst has restored his original and correct church once again upon the earth in it's fulness.

Didil