2 John 1:9-11

9 Everyone transgressing and not abiding in the doctrine of Christ does not have God. He who abides in the doctrine of Christ, he has both the Father and the Son.

10 If anyone comes to you and does not bring this doctrine, do not receive him into [your] house, nor speak a greeting to him.

11 For he who speaks a greeting to him is partaker of his evil deeds.