Do you think that 1 Thes. 3:13 is a passage talking about what John describes in Rev. 19 as the second coming with the saints, or do you think this is a rapture passage talking about Jesus coming to bring the souls of the brethren back with him?
1 Thes. 3:13 says, “May he strengthen your hearts so that you will be blameless and holy in the presence of our God and Father when our Lord Jesus comes with all his holy ones.”
In both First and Second Thessalonians the Second Coming is mentioned at least once in every chapter, for an average of once every thirteen verses. 1 Thes 3:13 is one of them. But the thing I like most about this one is that Paul was praying the Thessalonian believers would be “blameless and holy in the presence of our God and Father when our Lord Jesus comes with all His holy ones.”
You can debate whether Paul thought the 2nd coming would happen during his lifetime or not, but you can’t dispute the fact that by praying they would all be saved and in heaven when it happened, he was seeing the rapture and the 2nd coming as two separate events with believers being in Heaven with God before the time of 2nd Coming.