3:6-10 Thankfulness to God is very imperfect in the present state; but one great end of the ministry of the word is to help faith forward. That which was the instrument to obtain faith, is also the means of increasing and confirming it, namely, the ordinances of God; and as faith cometh by hearing, so it is confirmed by hearing also.
8. now—as the case is; seeing ye stand fast.
we live—we flourish. It revives us in our affliction to hear of your steadfastness (Ps 22:26; 2Jo 3:4).
if—implying that the vivid joy which the missionaries "now" feel, will continue if the Thessalonians continue steadfast. They still needed exhortation, 1Th 3:10; therefore he subjoins the conditional clause, "if ye," &c. (Php 4:1).