There is a difference between the pagan things Christianity added to their religion and the ones the Islam added. This difference lays in the point of origin. Christianity originates in Israeal where the people already believed in the 1 god idea from jewism.
The Islam comes from a place where the 1 god idea wasn't accepted yet. So therefore the writers of the islam had to the chance to put Jinns and other "pagan" stuff in the Koran rightaway.
The authors of the Bible had no such things to put in, so therefore you won't find them in the Bible. Perfectly logical. The pagan influences were only encoutered at a later stage when the religion started to spread out and when the Bible was already written.
So yes, there is a big difference, but it is one that can be explained.