2 John 1:9-11

9 Everyone who goes ahead and does not remain true to what the Messiah has taught does not have God. Those who remain true to his teaching have both the Father and the Son.

10 If someone comes to you and does not bring this teaching, don’t welcome him into your home. Don’t even say, “Shalom!” to him;

11 for the person who says, “Shalom!” to him shares in his evil deeds.