Fourthly, remission of sin is promised for Christ’s sake. Therefore, no one can obtain it, unless by faith alone. For no one can take hold of the promise or participate in it, except through faith only. Rom. 4:16, “Therefore it is of faith, that it might be by grace; to the end the promise might be sure.” Precisely as if he should say, that if our salvation and righteousness depended on our own merit, the promise of God would yet be uncertain and useless to us; for we could never know it with certainty, when our merits would suffice. The pious heart and Christian conscience know this full well, and would not for a thousand worlds that our salvation depended upon ourselves.
Paul agrees with this view, Gal. 3:22, “The Scripture hath concluded all under sin, that the promise by faith of Jesus Christ might be given to them that believe.” Here Paul casts aside all our merit; for he says we are all worthy of death, and concluded under sin; he calls to mind the divine promise, by which alone we can obtain the forgiveness of sin; and further adds how we become participants of the promise, namely, by faith. This argument, drawn by Paul from the very nature of the divine promise, namely, that as God’s promise is certain and must remain sure, (as it will not fail to do,) remission of sin cannot proceed from our merit; else it would be uncertain, and we could not know when our merits would suffice; yes, I say, this argument, this foundation, is a firm rock; it is almost the strongest in the whole of Paul’s writings, and is very often repeated and quoted in all the epistles. (Henkel Translation, p. 173-174).