Pro tip : very, very bad.
Some additional thoughts.
Mankind is based in reality. Religion is not. In fact most religion is anti-reality, anti-earth, anti-man. (And hence, they are all based on altruism).
Because religion is not grounded in reality, it stands to reason that all religions will have a net-negative effect on mankind. The various forms of Christianity are no exception. Anything else is probably wishful thinking.