The names of these two men are not mentioned anywhere else in the Bible. It seems that they were two of the magicians who resisted Moses (Exodus 7:11) and who set their miracles against those of Moses and Aaron. It is not certain where the apostle discovered their names; but they are frequently mentioned by the Hebrew writers, and others. As a result, there can be no reasonable doubt that their names were correctly handed down by tradition. It is very likely that the names of the more outstanding magicians who attempted to imitate the miracles of Moses would be handed down by tradition; and though they are not mentioned by Moses himself, and the Jews have told many ridiculous stories respecting them, yet this should not lead us to doubt the truth of the tradition respecting their names.
So Paul appears to be alluding to a tradition that these two men, Jannes and Jambres, did magic. They were evil men who were against the truth of God. They opposed Moses and Aaron whom God sent to free the Jews from Egypt. Paul says that the false teachers are just like those evil men. What they were doing was not identical but, like those men, they are enemies of the truth. In the final analysis, they are working against God. They have believed a lie and there is no truth with them. The evil which they have accepted has ruined them. Their minds have become wicked. They can no longer know what is true or receive it. They have denied the truth of God.
Sometimes it looks as though the pedlars of error are winning, they may seem to succeed. But that success will not last long. The truth will win in the end. In due time, all will see the true character of these teachers. They are utterly foolish to oppose the truth.
Paul spares no blushes attacking these teachers of error. He say that these heretics “resisted the truth” and were men “of corrupt minds”, whose understanding was perverted, biased and prejudiced against the truth; they are “reprobate concerning the faith” – the term means castaway, rejected, concerning the true faith – in other words, they are very far from being true Christians. Heresy cannot be tolerated. There is no middle ground. When truth is rejected, those who preach error are, and will be, rejected.