They knew it could be perverted and wrote it about it often and early. Half of Paul's early letters were complaining about derelict churches and their insane practices.

Which sort of highlights the point. Christianity is a faith. It cannot be perverted. It is either correct or it is not.

Institutions can become corrupted from the inside. It why I think people should look carefully at the words of Christ for advice on churches. It seems to be mostly ignored. Paul would have done well to remember what he was told.