The apostle tacitly upbraids them for their forgetfulness. To forget the things that have been taught us, is a great evil: Solomon often cautions against it, Proverbs 3:1, Proverbs 4:5; and it is often reproved, Hebrews 12:5 James 1:24; and the contrary required, Zechariah 4:4 1 Thessalonians 16:4 Judges 1:17 Revelation 3:3. David hid the word in his heart, Psalms 119:11, and the virgin Mary kept the angel's sayings, Luke 2:19. The apostles did take care to tell the churches of the apostacy that would come, and of false prophets and teachers that would arise, as Paul the elders of Ephesus, Acts 20:29,30, and Peter, 2 Peter 2:1, and St. John of the coming of antichrist, 1 John 2:18; and more fully, though obscurely, in the book of the Revelation; and the apostle here in this verse minds these Thessalonians that he told them of the coming of the man of sin before the coming of Christ, so that they should not have been shaken in their minds about Christ's coming in that present age. And they told the churches of these things, that they might not be surprised by them, or offended at them, when they came.
Related Commentaries of 2 Thessalonians 2:5
2 Thessalonians 2:5
5 Remember ye not, that, when I was yet with you, I told you these things?