2 Thessalonians 3:13-15

And as for [the rest of] you, believers, do not grow tired or lose heart in doing good [but continue doing what is right without weakening]. Now if anyone [in the church] does not obey what we say in this letter, take special note of that person and do not associate with him, so that he will be ashamed and repent. Do not regard him as an enemy, but keep admonishing him as a [believing] brother.