‘And then will be revealed the lawless one, whom the Lord Jesus will slay with the breath of his mouth, and bring to nothing by the manifestation of his coming.'
Note the continued emphasis on lawlessness. ‘The man of lawlessness -- the mystery of lawlessness (his hidden teaching now revealed and contrary to the Law) -- the lawless one.' Here is one who is completely opposed to the Law of God. All restraint will be cast off. Note also the emphasis on his being ‘revealed' (2 Thessalonians 2:5; 2 Thessalonians 2:6; 2 Thessalonians 2:8). He will be for a time hidden but will then be revealed, as the sphere in which he operates, his world, wherever it is, acknowledges him. So for a time he will develop his power, with the world unaware of his presence, and gradually he will build up his authority and control. Perhaps as a leading figure in the United Nations. Perhaps as an Arab dictator supported by the Arab nations. Perhaps as an influential leader in Europe. Who knows? But wielding great influence for evil. And then finally becoming a superhero, and probably a leading religious figure, receiving worship for himself in one sphere or another. That he will affect world issues is clear. But the world he controls will be his own ‘world', not necessarily the world at large (‘world' in Scripture denotes the world in which the writer lives, not the whole world). Parts of the world may well only be indirectly affected by him.
‘Whom the Lord Jesus will slay with the breath of his mouth, and bring to nothing by the manifestation of his coming.' The end of the man of sin is brought about by the manifestation of the coming of Christ. For Jesus Himself will come, not only to take His own, but to manifest Himself to the world in authority, brightness and glory. Then this powerful ‘man of sin' will be ‘brought to nothing', rendered powerless and emasculated, because his lawlessness will be shown for what it is by the coming of the Judge, Who will pass judgment on him and those who followed him by ‘the breath of His mouth' (compare Revelation 19:15 also Isaiah 11:4). The ‘breath of His mouth' once acted powerfully in creation (Psalms 33:6), now it will act equally powerfully in destruction.