Romans 4:13-25
On Law, Faith, and Righteousness
13It was not through law that Abraham and his offspring received the promise that he would be heir of the world, but through the righteousness that comes by faith. 14For if those who live by law are heirs, faith has no value and the promise is worthless, 15because law brings wrath. And where there is no law there is no transgression.
16Therefore, the promise comes by faith, so that it may be by grace and may be guaranteed to all Abraham's offspring—not only to those who are of the law but also to those who are of the faith of Abraham. He is the father of us all. 17As it is written: "I have made you a father of many nations." He is our father in the sight of God, in whom he believed—the God who gives life to the dead and calls things that are not as though they were.
18Against all hope, Abraham in hope believed and so became the father of many nations, just as it had been said to him, "So shall your offspring be." 19Without weakening in his faith, he faced the fact that his body was as good as dead—since he was about a hundred years old—and that Sarah's womb was also dead. 20Yet he did not waver through unbelief regarding the promise of God, but was strengthened in his faith and gave glory to God, 21being fully persuaded that God had power to do what he had promised. 22This is why "it was credited to him as righteousness." 23The words "it was credited to him" were written not for him alone, 24but also for us, to whom God will credit righteousness—for us who believe in him who raised Jesus our Lord from the dead. 25He was delivered over to death for our sins and was raised to life for our justification.
St. Paul teaches us that the law God gave Moses the law to write about...It was how one was to live...The moral conduct, how one would interact on earth and with others...But, and this is important, if all we had to do to get to heaven was to follow these Mosaic Laws, then we would not need faith... Faith would then have no value...
But it is faith, not the law, that is important...
It is by faith in God, and through God's grace (not the law) that gives life to the dead and gets us to heaven...Abraham, our patriarch, on earth had faith...He was close to one hundred years old, and Sarah in her nineties when God told him (Abraham) he would have a child...Abraham held on to that faith and had a child with Sarah, named Isaac...
Abraham had faith and kept that faith was fully persuaded that God, and gave the couple a child, named Isaac...Abraham, by keeping this faith was credited with righteousness...Their was no Mosaic Law to obey yet...Moses was not born, until much later...So Abraham could not follow the law (there was no written law), but Abraham followed his faith in God...
St. Paul teaches us that this righteousness, was not written for Abraham alone...Our credit of righteousness is given to us when we believe in Him, who raised Jesus our LORD from the dead...Jesus was brought to death for our sins and was raised to life for our justification...We are made acceptable to God, by believing God raised Jesus for us...Jesus pays and paid the price for our sins and guilt...