What does 2 John 1:10 mean?

John builds on his teaching from verses 7–9 with a conditional statement. The teaching he refers to is the one that Jesus came in real, physical, human form (John 1:1–14). The gospel of John, written by this same author, strongly emphasizes that Jesus came from heaven to earth: He "became flesh and dwelt among us" (John 1:14). Believers must accept that Jesus walked the earth as both divine and fully human. To deny this truth is to deny a core aspect of the gospel.

According to John, those who rejected this truth were not to be given any support. If a traveling teacher, who did not accept the humanity of Jesus, came to this church, John commands separation. They are not to be given resources, hospitality, or any other help. Believers are not to associate themselves in any way with false teachers who deny the true identity of Jesus. The following verse offers an additional reason for John's command, where he refers to the danger of sharing in the evil of these false teachers.