The other element—the second weapon—which his readers have and the false teachers do not have, is the Holy Spirit who indeed teaches the Christian by making the Word come alive for him and who abides in him.

The mention of lies versus truth in verse 21 leads John quite naturally to an analysis of the Gnostics’ errors. But it is not their errors in general that he seizes upon but rather the fundamental error which is their denial that Jesus is the Christ. Indeed, as he states it, this is not only the Gnostics’ error but also the most fundamental error that can be made by anyone. Therefore, it also has the most serious consequences. In writing about this denial of Jesus as the Christ John calls it the lie and the one who embraces it the liar.

Over against the antichrists who have left the church John sets God’s true children. These are distinguished by two essential characteristics: first, they have been anointed by the Holy One and second, they all know the truth centered in the Lord Jesus Christ.

Being faced with a major defection in their ranks, the Christians of Asia Minor might be tempted to be discouraged, but now John adds that the defection has a good purpose. These “went out” from us, he says, “that they might be made manifest that they were not all of us.” In other words, the defection has the effect of purifying the church and revealing both truth and error in true colors.

It is a characteristic of our time, often pointed out by contemporary Christian apologists, that men and women no longer strictly believe in truth. To be sure, they do use the term in a certain colloquial sense, referring to that which is the opposite of false; nevertheless, most twentieth-century men do not mean that when a thing is said to be true it is therefore true absolutely and forever.