1 Thessalonians 1:10
And to wait for his Son from heaven, whom he raised from the dead, [even] Jesus, which delivered us from the wrath to come.
Note 16 at 1Th 1:10: The Thessalonians had not only repented and turned from idolatry to serve the true and living God; they also awaited the appearing of Jesus Christ from heaven. Paul introduced here the theme of Christ's return that he discussed later in detail in 2 Thessalonians. In this letter, he referred at least five times to the return of Jesus Christ, once in each chapter (1Th 1:10, 2:19, 3:13, 4:16, and 5:23). His return will reveal two things: (1) It will be the "blessed hope" and the final manifestation of the salvation of the believer (Tit 2:13 and Heb 9:28); and (2) it will reveal the final manifestation of God's personal opposition to evil, resulting in judgment for the unbeliever (2Th 1:7-10).
Note 17 at 1Th 1:10: The "wrath to come" that the believer has been delivered from is the wrath or judgment that people will face because of their sins. God determined that the just punishment for sin would be eternal separation from Him. This separation is also referred to as "death" (Ro 6:23). God devised a plan to place the death penalty for sin upon His Son (Jesus Christ) when He suffered and died upon the cross. Because of that death, God offers the forgiveness of sins and eternal life to all who will repent and believe upon Christ (Ac 16:31 and 20:21).
For those who do not obey the Gospel of our Lord Jesus, there will be a day of wrath and vengeance (2Th 1:8 and 1Pe 4:17). Those who receive forgiveness through faith in what Jesus has already suffered will not come into judgment again. Their judgment has been placed on Jesus.