2 John 1:11
Whoever greets such a person shares in his evil deeds.
What it says
Whoever supports such a person shares in that person's evil deeds.
What it is doing
This verse closes the warning by showing the moral seriousness of aiding false teaching.
In context
7For many deceivers have gone out into the world, refusing to confess the coming of Jesus Christ in the flesh. Any such person is the deceiver and the antichrist. 8Watch yourselves, so that you do not lose what we have worked for, but that you may be fully rewarded. 9Anyone who runs ahead without remaining in the teaching of Christ does not have God. Whoever remains in His teaching has both the Father and the Son. 10If anyone comes to you but does not bring this teaching, do not receive him into your home or even greet him. 11Whoever greets such a person shares in his evil deeds.