Titus 3:9-11

But avoid foolish and ill-informed and stupid controversies and genealogies and dissensions and quarrels about the Law, for they are unprofitable and useless. After a first and second warning reject a divisive man [who promotes heresy and causes dissension—ban him from your fellowship and have nothing more to do with him], well aware that such a person is twisted and is sinning; he is convicted and self-condemned [and is gratified by causing confusion among believers].