Brothers who are beloved by God, we know that He has chosen you,
4 Knowing, brethren beloved. The participle knowing may apply to Paul as well as to the Thessalonians. Erasmus refers it to the Thessalonians. I prefer to follow Chrysostom, who understands it of Paul and his colleagues, for it is (as it appears to me) a more ample confirmation of the foregoing statement.
I. The apostle begins with thanksgiving to God. Being about to mention the things that were matter of joy to him, and highly praiseworthy in them, and greatly for their advantage, he chooses to do this by way of thanksgiving to God, who is the author of all that good that comes to us, or is done by us, at any time.
Commenting on 1 Thessalonians 1:2-5
Knowing, brethren beloved, your election of God. Which intends not an election to an office, for this epistle is written not to the officers of the church only, but to the whole church; nor to the Gospel, the outward means of grace, since this was common to them with others, and might be known without the evidence after given; nor does it design the effectual...