and to give relief to you that are afflicted with us, when the Lord Jesus is revealed from heaven with his mighty angels in flaming fire,
"With us" is according to Paul’s habit of identifying his experience with that of his Christian readers. See 1 Corinthians 4:8, Romans 8:23; Philippians 1:29-30; Philippians 2:18; Philippians 3:20-21; 2 Corinthians 1:7 (Vincent, Vol II 948).