Charles Ellicott Commentary 1 Thessalonians 2:1

"For yourselves, brethren, know our entering in unto you, that it hath not been found vain:" — 1 Thessalonians 2:1 (ASV)

For you yourselves, brothers, know.—The writers’ purpose is practical, not didactic; they therefore animate their converts with the stirring memories of their conversion. “We do not need to go to these foreign witnesses for the tale of how we came to you; for you recollect it as if it were yesterday.” The “for” (as in 1 Thessalonians 1:8) implies “for in fact,” “for after all.” The thought of 1 Thessalonians 1:5 and 1 Thessalonians 1:9 is here resumed, but with a different purpose: there it was to prove that the work was God’s work; here, to stir up their pure minds by way of remembrance.

Not in vain draws a little too much attention to the result of their coming. It should be, not vain—that is, not purposeless and idle. This may be seen from the contrast drawn in the following words.