Romans 4:3 - Matthew Poole's English Annotations on the Holy Bible

The scripture referred to is in Genesis 15:6. The apostle a little varies the words; in Genesis it is he believed in God, but here he believed God: again, in Genesis it is expressed actively, he counted it to him for righteousness; but here passively, it was counted to him for righteousness. The answer is, That the apostle in both followed the Septuagint, which was then more in use than the Hebrew text; and both are capable of an easy reconciliation, the difference being more in sound than in sense. Abraham believed God; i.e. the promises of God: that he would be his shield and exceeding great reward, Genesis 15:1; that he would give him an heir of his body, Genesis 15:4; that he would multiply his seed, Genesis 15:5, whereby he understood not only his fleshly seed, but also the Messiah, the Saviour of the world, which was come of his loins; He took on him the seed of Abraham, Hebrews 2:16. And besides these promises in Genesis 15:1-21, he believed that promise which was made him, Genesis 12:3, That in him and his seed all families of the earth should be blessed. That in these promises the Messiah is understood, is evident from Galatians 3:8,16; and that Abraham had an eye to him is evident, without exception, from 1 Thessalonians 8:56. It was counted unto him for righteousness; i.e. he was justified thereby: to have faith imputed for righteousness, and to be justified by faith, is the same thing. Faith is not our righteousness materially, but objectively and organically, as it apprehends and implies the righteousness of Christ, which is the matter of our justification. Our adversaries the papists oppose the imputation of Christ's righteousness to us; they cavil at the very word, and call it putative righteousness: and yet the apostle useth the word ten times in this chapter, and in the same sense that word ten times in this chapter, and in the same sense that we take it. But how shall we reconcile our apostle with St. James, about the manner of Abraham's justification: he says expressly, James 2:21, that Abraham our father was justified by works, when he offered his son Isaac; and thence he infers, Romans 4:24, that by works a man is justified, and not by faith only. They are easily reconciled, forasmuch as the one discourseth of the cause of our justification before God; the other, of the signs of justification before men. The one speaks of the imputation of righteousness; the other, of the declaration of righteousness. The one speaks of the office of faith; the other, of the quality of faith. The one speaks of the justification of the person; the other, of the faith of that person. The one speaks of Abraham to be justified; the other, of Abraham already justified.