2 John 1:7-11 NASB
For many deceivers have gone out into the world, those who do not acknowledge Jesus Christ as coming in the flesh. This is the deceiver and the antichrist. Watch yourselves, that you do not lose what we have accomplished, but that you may receive a full reward. Anyone who goes too far and does not abide in the teaching of Christ, does not have God; the one who abides in the teaching, he has both the Father and the Son. If anyone comes to you and does not bring this teaching, do not receive him into your house, and do not give him a greeting; for the one who gives him a greeting participates in his evil deeds.
NASB: New American Standard Bible