In this chapter, Paul described the end of the world and Christ's second coming (parousias, "presence") because some thought it had already come, but it had not. He said two things had to happen first:
1) Apostasy - a distinguishable falling away from and rebellion against the Lord
2) Appearance of the man of lawlessness, doomed to destructionThe man of lawlessness is recognized by commentators as the Antichrist (1 John 2:18, 22; 4:3; 2 John 7). This will be the last great world dictator. God declared war on Satan and his family in Genesis 3:15 and promised that the descendant of Eve (Jesus) would be the one who would bruise him on the head. This is Satan's last stand, and the Antichrist is his production. Those who are perishing and who do not believe the truth will worship Satan and believe his lies (Revelation 6:1-2; Daniel 9:24-27; Revelation 13:15-17; 19:11-21).
The day of the Lord is described as a time of suffering and trouble. The man of lawlessness may be coming, but evil will not have the upper hand because Christ will come to judge the world.
Paul talks about a few of the signs involved (as Jesus did in Mark 13), but his major emphasis is on how each person can prepare for His coming. He makes this transition in 2:13-17 by exhorting the Thessalonians to "stand firm" in the teachings that they had already been taught. They would not suffer the same fate as those who are perishing (2:10) because they had been chosen by God for salvation. Neither will we! This chapter concludes with Paul's prayer for encouragement and strength.
Are you standing firm? This is the best way to prepare for His coming.
Lord, thank You for choosing us for salvation, not because of anything that we have done on our own. Thank You for Your grace. Help us to stand firm in the midst of trouble and suffering and to hope for the glorious appearing of Jesus Christ. Amen.