1 John 5:21

Keep yourselves safe. The false gods were probably not idols such as were at Ephesus and Athens. John is certainly speaking about the false ideas of God which the false teachers substituted for the picture of God which Christ gives us in what he says. Compare Galatians 1:6-9. But it could be that the false teachers encouraged their followers to join in the worship of idols (compare Revelation 2:14; Revelation 2:20 and notes). The Christian who follows false gods puts himself in the Devil's power!!!