John’s first letter addresses a setting in which some people in the local church had departed the fellowship(2:19), apparently because their doctrine, ethics, devotion, or some combination of these conflicted with those of the church. 2nd John To be fervent in Christian love and watchful of deceivers. The writer planned to see the writer soon. 3rd John Is the shortest book of the new testament. Truth, love, and the goodness of God are predominant themes.
