The antichrists were not total strangers to the church; they once had been in the church, but they did not really belong to it. John does not say why they left; it is clear that their reasons for joining in the first place were wrong. Some people may call themselves Christians for less than the best reasons. Perhaps going to church is a family tradition. Maybe they like the social and business contacts they make there. Or possibly going to church is a long-standing habit, and they have never stopped to ask themselves why they do it. What is your main reason for being a Christian? Unless it is a Christ-centered reason, you may not really belong. You don't have to settle for less than the best. You can become personally acquainted with Jesus Christ and become a loyal, trustworthy follower.
- LAB Study Bible
1 John 2:18-19 (NLT) Dear children, the last hour is here. You have heard that the Antichrist is coming, and already many such antichrists have appeared. From this we know that the last hour has come. These people left our churches, but they never really belonged with us; otherwise they would have stayed with us. When they left, it proved that they did not belong with us.
