Is Christianity based on older myths?

[robvalue]

Interesting.

I get the idea that there may have been one author and so just call him "Paul". But I'm thinking that someone at that time could just write a bunch of stuff, write some letters, creating the character of "Paul" as the author. It's quite possible they'd have the knowledge to make the character convincing. It doesn't mean that they actually did any of the things they described, does it?

As I said I'm unsure about this one. What I'm asking is, is there good reason to think the author of Paul actually did any of the things he said or actually sent letters regarding stuff he had done and not just made up? Obviously him or someone else was adding stuff to it on the supernatural end, or else Paul was mentally ill.

If this was just "the kind of thing this kind of person might do" then that seems suspiciously indistinguishable from a fiction. Are there independent sources outside of the bible which back him up?