The letter seeks to encourage an audience enduring persecutions and trials by telling them that God will severely punish the people who are causing the hardships.
This passage offers frightening promises about a coming judgment as it looks forward to the Lord Jesus’ eventual return as an event accompanied by “blazing fire” and “powerful angels.” There is little description of the benefits or rewards that will come to Jesus’ beleaguered people beyond general mention of God providing them with relief and them responding by marveling at Jesus is the Messiah whose life, death, and resurrection are God's saving act for humanity More. The implication is that solace might come, instead, from what is said about persecutors and “those who do not know God and do not obey the gospel of our Lord Jesus.” As for those people, God “will pay back trouble” to the former and will unleash “everlasting destruction” on the latter.
This passage offers a very different outlook on Jesus’ return compared to 1 Thessalonians 4:13-5:11, where the focus is on being with Christ and there is no mention of judgment or punishment. Indeed, in all the letters that give no real reason to doubt that A Christian missionary who once persecuted the church More wrote them (viz., Romans, 1-2 Corinthians, Galatians, Philippians, 1 Thessalonians, and Philemon), there is no mention of postmortem punishment.
Descriptions of judgment as divine retribution or payback in a passage like this and in the book of Revelation can be upsetting. They risk making God appear bloodthirsty or unforgiving. They can insinuate that revenge is a balm for injustice, or that it motivates people to endure their own suffering. At the same time, they can give hope to people who feel as though God has forgotten them or whose sufferings are so severe that justice appears to be a foolish hope.