John Calvin Commentary 1 Thessalonians 1:6

"And ye became imitators of us, and of the Lord, having received the word in much affliction, with joy of the Holy Spirit;" — 1 Thessalonians 1:6 (ASV)

And you became imitators. To increase their eagerness, he declares that there is a mutual agreement, and harmony, as it were, between his preaching and their faith. For unless people, on their part, respond to God, no progress will result from the grace that is offered to them—not as if they could do this by themselves, but since God, as He begins our salvation by calling us, perfects it also by shaping our hearts to obedience.

The sum, therefore, is this—that an evidence of Divine election showed itself not only in Paul’s ministry, insofar as it was equipped with the power of the Holy Spirit, but also in the faith of the Thessalonians, so that this conformity is a powerful testimony to it. He says, however, “You were imitators of God and of us,” in the same sense in which it is said, that the people believed God and his servant Moses (Exodus 14:13), not as if Paul and Moses had anything different from God, but because He worked powerfully through them, as His ministers and instruments. While you embraced. Their readiness in receiving the gospel is called an imitation of God for this reason: just as God had presented Himself to the Thessalonians in a generous spirit, so they, on their part, had voluntarily come forward to meet Him.

He says, with the joy of the Holy Spirit, so that we may know that it is not by the prompting of the flesh, or by the inclinations of their own nature, that people will be ready and eager to obey God, but that this is the work of God’s Spirit. The circumstance that, amidst much tribulation, they had embraced the gospel serves to amplify this.

For we see many people, not otherwise averse to the gospel, who nevertheless avoid it, being intimidated by fear of the cross. Those, accordingly, who do not hesitate boldly to embrace along with the gospel the afflictions that threaten them, provide in this an admirable example of greatness of spirit. And from this it is all the more apparent how necessary it is that the Spirit should aid us in this.

For the gospel cannot be properly or sincerely received unless it is with a joyful heart. Nothing, however, is more contrary to our natural disposition than to rejoice in afflictions.