Romans 4:17

For He had compassion on us, and mercifully saved us, observing the many errors in which we were entangled, as well as the destruction to which we were exposed, and that we had no hope of salvation except it came to us from Him. For He called us when we were not, and willed that out of nothing we should attain a real existence.

The dead here are those whose souls have sinned, for Scripture says: "The soul that sins will die." For just as the senses perish in our mortal body so that the body can no longer hear, smell, taste or touch, so also the spiritual senses perish in the soul so that it cannot see God or hear his Word, or sense the sweet odor of Christ, or taste the good Word of God, or handle the word of life. People like that must be said to be dead. This is what we were like when Christ came, but he has given us life by his grace.

Paul confirms by quoting the law that Abraham is the father of all who believe, and so the promise is firm if they abandon the law on account of their faith, because the promise of the kingdom of heaven is given to the righteous, not to sinners. Those who are under the law are under sin because all have sinned, and it is not possible for anyone who is under the law to receive grace.In order to teach that there is one God for all, Paul tells the Gentiles that Abraham believed in God himself and was justified in his sight. The Gentiles also believe in him that they may be justified, and so there is no difference between Jew and Greek in faith, for when the circumcision and the uncircumcision are taken away they are made one in Christ.
Paul invites the Gentiles to share the faith of Abraham, who believed God while he was still uncircumcised. Now that that faith is preached in Christ, he has been raised from the dead, along with his wife. For when they were already very old they sprang back to life, so that Abraham did not doubt that he would have a son by Sarah, whom he knew to be sterile and who had long since ceased to have her menstrual period. Paul said this so that they would not worry about circumcision or uncircumcision but that they would respond eagerly because of their faith, secure in the knowledge that the one in whom they believe is no other than the one who gives life to the dead, who has the power to bring things which do not exist into being by his will.

Do you observe that this was ordered by Providence from of old? What then, he means, does He say this on account of the Ishmaelites, or of the Amalekites, or of the Hagarenes? This however, as he goes on he proves more distinctly not to be said of these. But as yet he presses forward to another point, by which means he proves this very thing by defining the mode of the relationship, and establishing it with a vast reach of mind.

But his meaning is something of this sort, as God is not the God of a part, but the Father of all, so is he also. And again, as God is a father not by way of the relationship of nature, but by way of the affiance of faith, so is he also inasmuch as it is obedience that makes him father of us all. For since they thought nothing of this relationship, as clinging to that grosser one, he shows that this is the truer relationship by lifting his discourse up to God. And along with this he makes it plain that this was the reward of faith that he received. Consequently, if it were not so, and he were the father of all the dwellers upon earth, the expression before (or answering to) would be out of place, while the gift of God would be curtailed.

For if He could "quicken the dead" and bring in "those things that were not as though they were," then could He also make those who were not born of him to be his children. And this is why he does not say, bringing in the things which are not, but calling them, so showing the greater ease of it. For as it is easy to us to call the things which are by name, so to Him it is easy, yea, and much easier to give a subsistence to things that are not.

Abraham is the father of all believers, not just of the nation of Israel. "Life to the dead" is given to those who are dead for the purpose of bearing children, which is the context of the present discussion.

This means that faith is in the inner man, in the sight of God and not in human display, which is what the circumcision of the flesh is.

Everything which God did not beget of himself but made through his Word he made not out of things which already existed but out of what did not exist at all, i.e., out of nothing.

Faith looketh upon something which existeth not as if it were something which doth exist, and that which existeth it accounteth as if it existed not. And this also is an example of the power of God, concerning Whom Paul spake, "He calleth the things that are not as though they were." Now these things the Spirit of God spake concerning the power of God, that those things which were not He called to come into existence, and that what did exist He called and changed into nothing. To this power also He compareth faith, not only in that matter of [the working] of signs and wonderful things, in that the things which are not it worketh after the manner of God, and those which are it bringeth to an end and finisheth by the power of God, but also in that those things which, because of their being hidden, were accounted as if they existed not, were perceived by it as if they were manifest, and those which are, and in which we labour, and by which we are ministered unto, are accounted as if they existed not, for [faith] saw aforetime their dissolution.

For as God is over created things so art thou god over thy lusts, and as by the will of the Creator created things exist, and if He willeth not they exist not, so also according to thy will are thy lusts, and at thy will they become nothing. "God calleth the things which are not as if they were," even so also doth thy will create the lusts which are not, that they may come into existence; now God looketh upon all things, and they become nothing, so also doth thy will look upon all the passions, and straightway they are destroyed and become nothing. If thou wishest, they are thy passions; and if thou wishest, they do not exist. From thee springeth up the cause of thy lust, and from thee is born the destruction thereof; if thou makest it to live, thou canst make it to die, and if thou makest lust to live in thee, thou makest thy life which is in God to die.

The meaning is as follows: Abraham is the father of all "before God," that is, in a manner similar to God. As God is the Father of all, so also is Abraham, not by natural kinship, but by the bond of faith. He added "whom he believed" in order to show that Abraham also received a reward for his faith—to be the father of all. Therefore, if you, O Jew, do not acknowledge that Abraham is the father of all, then you have diminished the honor which he received through faith.
Now he repeats what was said above, that is, that Abraham believed that God could not only revive his deadened flesh, such as his was, but also make it fruitful; which is why he now says: "who gives life to the dead." And the words "who calls those things which do not exist as though they did" he added in order to show that it is not impossible for God to make those who are not children of Abraham into his children. He did not say, however, "who brings into being that which does not exist," but "who calls." How easy it is for us to name something that exists, just as easy it is for God to bring into being that which does not exist.

Third, at before God, he explains what he had said. For I have made you seems to imply that something destined to be fulfilled in the distant future had already come to pass. However, things that are future in themselves are present in God's providence: before the universe was created, it was known to him; so it was also after it was finished (Sir 23:20). Accordingly, the Apostle says that the statement, I have made you, should be understood before God, i.e., in his presence, whom he believed. For Abraham had believed God promising things to come as if he saw them present, because, as is stated in Hebrews: faith is the assurance of things hoped for, the conviction of things not seen (Heb 11:1).

Then when he says who quickens the dead he shows by whom this promise is to be fulfilled, saying, who, namely, God, quickens the dead, i.e., the Jews, who were dead in sin for acting against the law; he vivifies with faith and grace to enable them to realize the promise to Abraham: as the Father raises the dead and gives them life so the Son gives life to whom he will (John 5:21).

And calls those things that are not, i.e., he calls the gentiles to grace as those that are, i.e., as the Jews: I will call that which was not my people, my people (Rom 9:25).

He refers to the gentiles as those things that are not, because they were completely estranged from God, and it is stated in 1 Corinthians: if I do not have charity, I am nothing (1 Cor 13:2). Consequently, through this call the promise to Abraham is fulfilled even in the gentiles.

Or, and calls those things that are not refers not to one's temporal calling but to the call of eternal predestination, because even those who are not, are called and chosen as if they were: he chose us in him before the foundation of the world (Eph 1:4). Concerning this call it is stated below: not of works but of him who calls, it was said to her: the elder shall serve the younger (Rom 9:12).

Or he is calling God's simple knowledge a call, or the knowledge by which he knows the future as present. This is the way it is taken in the Psalm: he calls the stars by their names (Ps 147:4). According to this sense, what is said here is mentioned on account of an earlier statement: before God, whom he believed.

Two things seem to militate against what was said: I have made you a father of many nations. One of these was that Abraham was as good as dead from old age. Against this he says, who quickens the dead. The other is that those many nations did not exist yet. Against this he says: and calls those things that are not, as those that are.