13 For the promise that he would be the heir of the world was not to Abraham or to his seed through the law, but through the righteousness of faith. 14 For if those who are of the law are heirs, faith is made void and the promise made of no effect, 15 because the law brings about wrath; for where there is no law there is no transgression. 16 Therefore it is of faith that it might be according to grace, so that the promise might be sure to all the seed, not only to those who are of the law, but also to those who are of the faith of Abraham, who is the father of us all
17 (as it is written, "I have made you a father of many nations") in the presence of Him whom he believed--God, who gives life to the dead and calls those things which do not exist as though they did; 18 who, contrary to hope, in hope believed, so that he became the father of many nations, according to what was spoken, "So shall your descendants be." 19 And not being weak in faith, he did not consider his own body, already dead (since he was about a hundred years old), and the deadness of Sarah's womb. 20 He did not waver at the promise of God through unbelief, but was strengthened in faith, giving glory to God, 21 and being fully convinced that what He had promised He was also able to perform. 22 And therefore "it was accounted to him for righteousness."
Matthew Henry's Commentary on Romans 4:13-22
Commentary on Romans 4:13-22
(Read Romans 4:13-22)
The promise was made to Abraham long before the law. It points at Christ, and it refers to the promise, Genesis 12:3. In Thee shall all families of the earth be blessed. The law worketh wrath, by showing that every transgressor is exposed to the Divine displeasure. As God intended to give men a title to the promised blessings, so he appointed it to be by faith, that it might be wholly of grace, to make it sure to all who were of the like precious faith with Abraham, whether Jews or Gentiles, in all ages. The justification and salvation of sinners, the taking to himself the Gentiles who had not been a people, were a gracious calling of things which are not, as though they were; and this giving a being to things that were not, proves the almighty power of God. The nature and power of Abraham's faith are shown. He believed God's testimony, and looked for the performance of his promise, firmly hoping when the case seemed hopeless. It is weakness of faith, that makes a man lie poring on the difficulties in the way of a promise. Abraham took it not for a point that would admit of argument or debate. Unbelief is at the bottom of all our staggerings at God's promises. The strength of faith appeared in its victory over fears. God honours faith; and great faith honours God. It was imputed to him for righteousness. Faith is a grace that of all others gives glory to God. Faith clearly is the instrument by which we receive the righteousness of God, the redemption which is by Christ; and that which is the instrument whereby we take or receive it, cannot be the thing itself, nor can it be the gift thereby taken and received. Abraham's faith did not justify him by its own merit or value, but as giving him a part in Christ.