Abraham was, humanly speaking, the founder of our Jewish nation. What were his experiences concerning this question of being saved by faith?
Was it because of his good deeds that God accepted him? If so, he would have had something to boast about. But from God's point of view Abraham had no basis at all for pride.
For the Scriptures tell us, "Abraham believed God, so God declared him to be righteous."
References for Romans 4:3
When people work, their wages are not a gift. Workers earn what they receive.
But people are declared righteous because of their faith, not because of their work.
King David spoke of this, describing the happiness of an undeserving sinner who is declared to be righteous:
"Oh, what joy for those whose disobedience is forgiven, whose sins are put out of sight.
Yes, what joy for those whose sin is no longer counted against them by the Lord."
References for Romans 4:8
Now then, is this blessing only for the Jews, or is it for Gentiles, too? Well, what about Abraham? We have been saying he was declared righteous by God because of his faith.
But how did his faith help him? Was he declared righteous only after he had been circumcised, or was it before he was circumcised? The answer is that God accepted him first, and then he was circumcised later!
The circumcision ceremony was a sign that Abraham already had faith and that God had already accepted him and declared him to be righteous -- even before he was circumcised. So Abraham is the spiritual father of those who have faith but have not been circumcised. They are made right with God by faith.
And Abraham is also the spiritual father of those who have been circumcised, but only if they have the same kind of faith Abraham had before he was circumcised.
It is clear, then, that God's promise to give the whole earth to Abraham and his descendants was not based on obedience to God's law, but on the new relationship with God that comes by faith.
So if you claim that God's promise is for those who obey God's law and think they are "good enough" in God's sight, then you are saying that faith is useless. And in that case, the promise is also meaningless.
But the law brings punishment on those who try to obey it. (The only way to avoid breaking the law is to have no law to break!)
So that's why faith is the key! God's promise is given to us as a free gift. And we are certain to receive it, whether or not we follow Jewish customs, if we have faith like Abraham's. For Abraham is the father of all who believe.
That is what the Scriptures mean when God told him, "I have made you the father of many nations." This happened because Abraham believed in the God who brings the dead back to life and who brings into existence what didn't exist before.
References for Romans 4:17
When God promised Abraham that he would become the father of many nations, Abraham believed him. God had also said, "Your descendants will be as numerous as the stars," even though such a promise seemed utterly impossible!
References for Romans 4:18
And Abraham's faith did not weaken, even though he knew that he was too old to be a father at the age of one hundred and that Sarah, his wife, had never been able to have children.
Abraham never wavered in believing God's promise. In fact, his faith grew stronger, and in this he brought glory to God.
He was absolutely convinced that God was able to do anything he promised.
And because of Abraham's faith, God declared him to be righteous.
Now this wonderful truth -- that God declared him to be righteous -- wasn't just for Abraham's benefit.
It was for us, too, assuring us that God will also declare us to be righteous if we believe in God, who brought Jesus our Lord back from the dead.
He was handed over to die because of our sins, and he was raised from the dead to make us right with God.