the doctrine that human nature was corrupted by the Fall. Catholics call it original sin. I believe Calvinists use the term depraved.

But that is not evil. If anything, it is a tendency to sin, to accept evil. Again, that does not make humans evil.

The whole story after Adam is the effort to return to that state in which we were created. The sole purpose of a church is to pave that road, no more, no less.