2John 1:7-11

7Many deceivers have gone out into the world, those who do not confess that Jesus Christ has come in the flesh; any such person is the deceiver and the antichrist!8Be on your guard, so that you do not lose what we have worked for, but may receive a full reward.9Everyone who does not abide in the teaching of Christ, but goes beyond it, does not have God; whoever abides in the teaching has both the Father and the Son.10Do not receive into the house or welcome anyone who comes to you and does not bring this teaching;11for to welcome is to participate in the evil deeds of such a person.