Matthew Henry Commentary Romans 4:13-22

"For not through the law was the promise to Abraham or to his seed that he should be heir of the world, but through the righteousness of faith. For if they that are of the law are heirs, faith is made void, and the promise is made of none effect: for the law worketh wrath; but where there is no law, neither is there transgression. For this cause [it is] of faith, that [it may be] according to grace; to the end that the promise may be sure to all the seed; not to that only which is of the law, but to that also which is of the faith of Abraham, who is the father of us all (as it is written, A father of many nations have I made thee) before him whom he believed, [even] God, who giveth life to the dead, and calleth the things that are not, as though they were. Who in hope believed against hope, to the end that he might become a father of many nations, according to that which had been spoken, So shall thy seed be. And without being weakened in faith he considered his own body now as good as dead (he being about a hundred years old), and the deadness of Sarah`s womb; yet, looking unto the promise of God, he wavered not through unbelief, but waxed strong through faith, giving glory to God, and being fully assured that what he had promised, he was able also to perform. Wherefore also it was reckoned unto him for righteousness." — Romans 4:13-22 (ASV)

The promise was made to Abraham long before the law. It points to Christ, and it refers to the promise in Genesis 12:3: In Thee shall all families of the earth be blessed. The law works wrath by showing that every transgressor is exposed to divine displeasure. As God intended to give people a title to the promised blessings, He appointed it to be by faith, so that it might be wholly of grace, to make it sure to all who were of the same precious faith as Abraham, whether Jews or Gentiles, in all ages.

The justification and salvation of sinners, and 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 bringing into being 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 fulfillment of His promise, firmly hoping when the case seemed hopeless.

It is weakness of faith that causes a person to pore over the difficulties in the way of a promise. Abraham did not consider it a point that would admit of argument or debate. Unbelief is at the bottom of all our wavering at God's promises. The strength of faith appeared in its victory over fears. God honors faith, and great faith honors God.

It was imputed to him for righteousness. Faith is a grace that, above all others, gives glory to God. Faith clearly is the instrument by which we receive the righteousness of God, the redemption that is by Christ; and that which is the instrument by which we take or receive it cannot be the thing itself, nor can it be the gift taken and received by it. Abraham's faith did not justify him by its own merit or value, but by giving him a part in Christ.