Separate themselves] RV 'make separations,' i.e. they break up the Church into parties and sects: cp. 1 Corinthians 1:12.
Sensual] RM 'natural or animal': cp. v. 10. Spirit] RV 'Spirit,' i.e. the Holy Spirit.
22, 23. And of some, etc.] RV 'and on some have mercy, who are in doubt; and some save, snatching them out of the fire; and on some have mercy with fear'; but RM, 'the Greek text in this passage (“and.. fire”) is somewhat uncertain.' The garment spotted by the flesh] cp. Zechariah 3:2. and Leviticus 13:47-59. There is contagion in their error like that of a plague. In their efforts to save others they must beware of this.