What if Christianity didn't conquer the Roman Empire, and Islam failed to take over Arabia, Central Asia or Persia. What would be different in society?

Who the fuck knows because it didn't happen.

Yeah there is really no way of even putting out a legitimate guess because the possibilities are infinite.

The European continent would still be daily raped by the vikings.

It would be like Asia, where you have temples preserved intact from 1000's of years ago, and traditions of learning and wisdom that survived the ages. Before the "people of the book" came along, there was meeting of minds between the Greek philosophers and the Buddhists in India. Alexander the Great was one of the first to start this dialog.

http://en.wikipedia.org/wiki/Greco-Buddhism

Pagan faith did survive it just changed into Judaism, then into Christianity and Muslim faiths.

Pagan religions changed after they passed from the realm of oral tradition into written tradition.

So nothing would be different if the pagan religions survived to the modern day in a different form. We would have religious nuts who call themselves by another name. But....

A religious nut by any other name, is still fucking insane.

I think he means this thread for speculation. Knowing what we do about people, cultures, and religions, I think there's a lot of good guessing possible.

FYI, there is a fascinating sub-genre of fiction known as "alternate history," in which writers start with an assumption--that the South won the Civil War, for instance--and take it from there.

One of the best--Iron Dream, by Norman Spinrad--postulates that Hitler came to America and got some fame as an S/F illustrator.

see

http://en.wikipedia.org/wiki/The_Iron_Dream

for more on Iron Dream

thats so true Judaism was like the first catholic church
the popes learned allot from them