1Now, brothers, concerning the coming of our Lord Jesus Christ and our gathering together to him, we ask you 2not to be quickly shaken in your mind or troubled, either by spirit or by word or by letter as if from us, saying that the day of Christ has already come. 3Let no one deceive you in any way. For it will not be unless the rebellion comes first, and the man of sin is revealed, the son of destruction. 4He opposes and exalts himself against all that is called God or that is worshiped, so that he sits as God in the temple of God, setting himself up as God. 5Don’t you remember that when I was still with you, I told you these things? 6Now you know what is restraining him, to the end that he may be revealed in his own season. 7For the mystery of lawlessness already works. Only there is one who restrains now, until he is taken out of the way. 8Then the lawless one will be revealed, whom the Lord will kill with the breath of his mouth and destroy by the manifestation of his coming; 9even he whose coming is according to the working of Satan with all power and signs and lying wonders, 10and with all deception of wickedness for those who are being lost, because they didn’t receive the love of the truth, that they might be saved. 11Because of this, God sends them a powerful delusion, that they should believe a lie, 12that they all might be judged who didn’t believe the truth, but had pleasure in unrighteousness.
13But we are bound to always give thanks to God for you, brothers loved by the Lord, because God chose you from the beginning for salvation through sanctification of the Spirit and belief in the truth, 14to which he called you through our Good News, for the obtaining of the glory of our Lord Jesus Christ. 15So then, brothers, stand firm and hold the traditions which you were taught by us, whether by word or by letter.
16Now our Lord Jesus Christ himself, and God our Father, who loved us and gave us eternal comfort and good hope through grace, 17comfort your hearts and establish you in every good work and word.
Coming (Gk. παρουσία, parousia). (3:13, Phil 1:26, 1Thess 5:23, 2Thess 2:8, James 5:8, 2Pet 3:12) Strong’s 3952
This is a compound noun formed from the preposition παρά (para), “alongside,” and a form of εἰμί (eimi), to “be.” This word means to be “present,” and may focus on the beginning of that presence, or “coming.” This verse speaks of the second coming of Jesus, and by using this word Paul emphasizes that the most important aspect of Jesus’ coming will be His presence. Jesus will be back in all the power of His glorious, ascended presence (see Rev 1:9-20). Things will change dramatically on earth when Jesus comes, changes He will effect up close and personally. This illustrates and emphasizes the importance and power of God’s presence, and indeed Jesus’ presence.