John Calvin Reformed @genevareformer

3 Blessed be God He begins (as has been observed) with this thanksgiving — partly for the purpose of extolling the goodness of God — partly, with the view of animating the Corinthians by his example to the resolute endurance of persecutions; and partly, that he may magnify himself in a strain of pious glorying, in opposition to the malignant slanderings of the false apostles.

Matthew Henry Presbyterian @wholebiblehenry

After the foregoing preface, the apostle begins with the narrative of God's goodness to him and his fellow-labourers in their manifold tribulations, which he speaks of by way of thanksgiving to God, and to advance the divine glory (Co2 1:3-6); and it is fit that in all things, and in the first place, God be glorified. Observe, I.

Commenting on 2 Corinthians 1:3-6

Albert Barnes Presbyterian @notesbybarnes

Verse 3. Blessed be God. This is the commencement, properly, of the epistle; and it is the language of a heart that is full of joy, and that bursts forth with gratitude in view of mercy. It may have been excited by the recollection that he had formerly written to them, and that during the interval which had elapsed between the time when the former...