he started the cult called christianity?

Nothing is wrong with Paul's writings. Something is wrong with Christianity. How are you going to blame an author, when there is a million people who give private interpretations of paul's writings. Peter warns in his books that Paul's writings can be easily misunderstood, because it takes lots of scriptures for Paul to explain what he is trying to say. And people only read a couple of scriptures, and then make a whole doctrine with it, which is ridiculous.

2 Peter 3:15-16 (King James Version)

15And account that the longsuffering of our Lord is salvation; even as our beloved brother Paul also according to the wisdom given unto him hath written unto you;

16As also in all his epistles, speaking in them of these things; in which are some things hard to be understood, which they that are unlearned and unstable wrest, as they do also the other scriptures, unto their own destruction.

People twist Paul's scriptures unto their own destruction. They twist his scriptures to say ANYONE WHO BELIEVES and CONFESSES THAT THE LORD DIED FOR THEIR SINS, they are saved. Which is a BIG LIE. That is not what Paul meant.