They went out from us [seeming at first to be Christians], but they were not really of us [because they were not truly born again and spiritually transformed]; for if they had been of us, they would have remained with us; but they went out [teaching false doctrine], so that it would be clearly shown that none of them are of us.

Beloved, if our heart does not convict us [of guilt], we have confidence [complete assurance and boldness] before God;

The one who habitually keeps His commandments [obeying His word and following His precepts, abides and] remains in Him, and He in him. By this we know and have the proof that He [really] abides in us, by the Spirit whom He has given us [as a gift].

Beloved, do not believe every spirit [speaking through a self-proclaimed prophet]; instead test the spirits to see whether they are from God, because many false prophets and teachers have gone out into the world.

They [who teach twisted doctrine] are of the world and belong to it; therefore they speak from the [viewpoint of the] world [with its immoral freedom and baseless theories—demanding compliance with their opinions and ridiculing the values of the upright], and the [gullible one of the] world listens closely and pays attention to them.