The Apostle Paul
Romans 6:17BSB·traditional attribution

But thanks be to God that, though you once were slaves to sin, you wholeheartedly obeyed the form of teaching to which you were committed.

John Calvin Reformed @genevareformer

17. But thanks be to God, etc. This is an application of the similitude of the present subject. Though they were only to be reminded that they were not now the servants of sin, he yet adds a thanksgiving; first, that he might teach them, that this was not through their own merit, but through the special mercy of God; and secondly, that by this...

Matthew Henry Presbyterian @wholebiblehenry

The apostle's transition, which joins this discourse with the former, is observable: "What shall we say then? Rom 6:1. What use shall we make of this sweet and comfortable doctrine? Shall we do evil that good may come, as some say we do? Rom 3:8. Shall we continue in sin that grace may abound?

Commenting on Romans 6:1-23

John Gill Reformed Baptist @doctorgill

But God be thanked that ye were the servants of sin,.... Not that the apostle must be thought to give thanks to God for that these persons had been the servants of sin, than which nothing is more disagreeable to God, or caused more shame to themselves; but that inasmuch as they had been in the drudgery and service of sin, they were now freed from it.