2 John 1:10-13

If anyone comes to you and does not bring this teaching [but diminishes or adds to the doctrine of Christ], do not receive or welcome him into your house, and do not give him a greeting or any encouragement; for the one who gives him a greeting [who encourages him or wishes him success, unwittingly] participates in his evil deeds. I have many things to write to you, but I prefer not to do so with paper (papyrus) and black (ink); but I hope to come to you and speak with you face to face, so that your joy may be complete. [Num 12:8] The children of your elect (chosen) sister greet you.