1Th 2:1-20. His Manner of Preaching, and Theirs of Receiving, the Gospel; His Desire to Have Revisited Them Frustrated by Satan.
1. For—confirming 1Th 1:9. He discusses the manner of his fellow missionaries' preaching among them (1Th 1:5, and former part of 1Th 2:9) at 1Th 2:1-12; and the Thessalonians' reception of the word (compare 1Th 1:6, 7, and latter part of 1Th 2:9) at 1Th 2:13-16.
yourselves—Not only do strangers report it, but you know it to be true [Alford] "yourselves."
not in vain—Greek, "not vain," that is, it was full of "power" (1Th 1:5). The Greek for "was," expresses rather "hath been and is," implying the permanent and continuing character of his preaching.