2 John 1:10

Notice how it is put. It does not say: he fails to bring the true humanity, or the proper Deity. The reason is that Satan might change the doctrine a little, so as to keep up appearances for simple people. So it would not do to name just one form of error. The devil would only have to avoid that form, and there would be no defence left. But here it stands firm and yet comprehensive: if a man comes to you and does not bring this doctrine (that is, the doctrine of Christ), do not receive him. It does not matter how the enemy has warped his soul and dishonoured Christ through him.

To do so would be encouraging and helping him; it means tampering with my own conscience, because I am allowing something to pass as Christ which is a false Christ, and the deepest dishonour to God. If I show this appearance of love where the truth is not, it is not Christ at all; it is denying Him, and saying that what is false is as good as what is true. It is helping the Antichrist and not the Christ. "He who greets him" (that is, literally salutes him on leaving) "shares in his evil deeds." It was a sign of recognition and companionship.

If such a person comes, of course without the doctrine, yet claiming the ground of truth, you are not to receive him. Where? At the Lord's table? No; the apostle could not have said that to the elect lady and her children. The exhortation is quite independent of public fellowship. They are not even to receive him into their private house, nor to greet him with ordinary courtesy.

This scripture applies first of all to teachers — to all who did not bring "the doctrine of Christ," that is, the truth about His person, and perhaps about His work too. Here the apostle is clearly concerned with those who move from place to place to teach. But then, "if anyone comes to you," and takes the place of a teacher in seeking to spread his errors, treat him as the apostle directs. Faithfulness to Christ makes it the responsibility of every head of a household to hold to the truth. So he must keep out of his house what would really undermine the foundations of Christianity.

The second letter of John settles it that being personally sound in the faith is not enough. The apostle carefully warns even a woman, the elect lady, and her children. They had a direct responsibility if they received someone who did not bring the doctrine of Christ… So the Holy Spirit lays down the principle plainly. The simplest believers who back someone who confesses a false Christ share in his evil deeds, even without taking in the evil doctrine themselves.

So we must test anyone who comes to the door: is it truly the doctrine of Christ he brings? If not, he is an enemy of Christ, though he himself may not realise it. We are not to show hostility. But in the fear of God we must firmly refuse any sign that could be taken as approving his evil. This would certainly mean taking no literature from him. There is to be no arguing, but refusal.

He had pressed the walk of love very strongly in the first letter. Here too he asks the lady that we love one another. It is not a new commandment, he says, but the one we have had from the beginning. Then he takes up these two guards of true love: one is the truth and the other is obedience.