The New Testament is very strong in the matter of not receiving one who denies the person of Christ. Even the second epistle of John is an epistle about loving one another here the apostle John prohibits us from sharing in heresy. 2 John 7 says, “For many deceivers went out into the world, those who do not confess Jesus Christ coming in the flesh. This is the deceiver and the antichrist.” We should not have any contact with heretics or false prophets.
The apostle John in his gospel and first epistle inoculated the believers with the mending ministry concerning the person of Christ against the heresies regarding Christ’s deity and humanity. Because of such an inoculating truth, we see in 2 and 3 John that he and all those who had known this truth love those who were faithful to this truth.