But for us also - For our use; (compare Romans 15:4; 1 Corinthians 10:11), that we might have an example of the way in which people may be accepted of God. It is recorded for our encouragement and imitation, to show that we may in a similar manner be accepted and saved.
If we believe on him ... - Abraham showed his faith in God by believing just what God revealed to him. This was his faith, and it might be as strong and implicit as could be exercised under the fullest revelation. Faith, now, is belief in God just so far as he has revealed his will to us. It is therefore the same in principle, though it may have reference to different objects. It is confidence in the same God, according to what we know of his will. Abraham showed his faith mainly in confiding in the promises of God respecting a numerous posterity. This was the leading truth made known to him, and this he believed.
(The promise made to Abraham was, “in thy seed shall all nations of the earth be blessed,” on which we have the following inspired commentary: “And the scriptures foreseeing that God would justify the pagan through faith, preached before the gospel unto Abraham, saying, In thee shall all nations be blessed,” Galatians 3:8. It would seem, then, that this promise, like that made immediately after the fall, contained the very germ and principles of the gospel. So that after all there is not so great difference between the object of Abraham’s faith, and that of ours. Indeed the object in both cases is manifestly the same.)
The main or leading truths that God has made known to us are, that he has given his Son to die; that he has raised him up; and that through him he is ready to pardon. To put confidence in these truths is to believe now. Doing this, we believe in the same God that Abraham did; we evince the same spirit; and thus show that we are the friends of the same God, and may be treated in the same manner. This is faith under the gospel (compare the notes at Mark 16:16), and shows that the faith of Abraham and of all true believers is substantially the same, and is varied only by the difference of the truths made known.