2 John 10-11 10If anyone comes to you and does not bring this teaching, do not receive him into your house and say to him a greeting, 11for the one who says a greeting has fellowship with his wicked works.
John warns the lady and her children one last time about false teachers. This verse highlights a possible active, practical response they should give to those who teach the wrong doctrine. Itinerant evangelists claiming to have the authoritative message were circulating among the areas where missionaries like Paul, Silas, Barnabas, Timothy, Peter, John, and others had gone. The Christian message was beginning to circulate. The message of eternal salvation was appealing and needed. However, the problem was syncretism and the blurring of religions. Some of these preachers might and may have already come to the area of the recipients of this letter and started preaching a false doctrine about Jesus, that either he was just a man (possibly taught by some of the Judaizers Paul had to deal with) or not really human, that he did not come in the flesh (an idea particularly influenced by Platonic and proto-Gnostic thought). The best defense against heresy is to know the truth of the gospel. That is what John urges the host and her disciples to know.
The warning should be lived out by not opening her home for close fellowship. Hospitality was a significant social practice in the first century, especially among Christians. Hospitality is represented in these verses with the verb fellowship (koiōnei). The basic idea behind this word means to share something in common. Fellowship in one’s home can express two ideas. One is to aid in the mission of compassion by welcoming people in for meals or a place to stay. Christians are directed in Hebrews 13:2 to do that even for strangers. A second aspect of fellowship is affirmation, where people join together because they have the same beliefs and can help and encourage one another in those beliefs. This type of fellowship is often found in New Testament passages, with one example being how the earliest believers gathered together in Acts 2:42.
The problem the lady host could experience has to do with the second aspect. If she welcomed these false teachers into her home, she was essentially saying that she agreed with them. This was not a matter of the first type of showing compassion and hospitality. To give a greeting could involve an acknowledgement in what these people taught. The typical Greek word for greeting is used here (chairein), which means rejoice, welcome, come on in, I’m glad to see you, let’s have a good time together. We cannot and should not have a good time of deep fellowship with people who reject Jesus and claim to speak the truth to us. We need to be cautious. The verb for fellowship is present tense, implying a continuous time together, not just having a non-believer over for a meal. We should not encourage false teaching, but keep it far away from our homes lest our faith be compromised. Such fellowship may only open the door to wickedness and sin.