Yes they do (the Gospels clearly describe supernatural events, and they are clearly documents written long ago in history), you may just choose to work from a presupposition that the supernatural events can't be real, but that is a case of reading your own presuppositions into the documents (which we all do, me included)Historical documents don't describe supernatural events.

Well, that's another topic really - we know that Christianity was established around the Mediterranean before Constantine's time which was how his wife had come to be a Christian before his conversion (whether his conversion was genuine or political).Christianity may not have take off if Constaine had not converted,,.