they may have been living under someone who was an anti christ but they were not living under the man of lawlessness spoken of in scripture - that kind of understanding is fact as it is elementary sense that all has to be fulfilled - just just a piece added to assumptions
John Calvin disagrees.
Here, however, the subject treated of is not the name of God himself, but his majesty and worship, and, in general, everything that he claims for himself. "True religion is that by which the true God alone is worshipped; that, the son of perdition will transfer to himself." Now, every one that has learned from Scripture what are the things that more especially belong to God, and will, on the other hand, observe what the Pope claims for himself -- though he were but a boy of ten years of age -- will have no great difficulty in recognizing Antichrist. Scripture declares that God is the alone Lawgiver (
James 4:12) who is able to save and to destroy; the alone King, whose office it is to govern souls by his word. It represents him as the author of all sacred rites; [644] it teaches that righteousness and salvation are to be sought from Christ alone; and it assigns, at the same time, the manner and means. There is not one of these things that the Pope does not affirm to be under his authority. He boasts that it is his to bind consciences with such laws as seem good to him, and subject them to everlasting punishment. As to sacraments, he either institutes new ones, according to his own inclination, [645] or he corrupts and deforms those which had been instituted by Christ -- nay, sets them aside altogether, that he may substitute in their place the sacrileges [646] which he has invented. He contrives means of attaining salvation that are altogether at variance with the doctrine of the Gospel; and, in fine, he does not hesitate to change the whole of religion at his own pleasure. What is it, I pray you, for one to lift up himself above everything that is reckoned God, if the Pope does not do so? When he thus robs God of his honor, he leaves him nothing remaining but an empty title of Deity, [647] while he transfers to himself the whole of his power. And this is what Paul adds shortly afterwards, that the son of perdition would shew himself as God. For, as has been said, he does not insist upon the simple term God, but intimates, that the pride [648] of Antichrist would be such, that, raising himself above the number and rank of servants, and mounting the judgment-seat of God, [649] would reign, not with a human, but with a divine authority. For we know that whatever is raised up into the place of God is an idol, though it should not bear the name of God.