From Augustine's Commentary on Psalm 47 (48)
"We have received your mercy, God, in the midst of your people." [Augustine's text is "in medio populi tui", though The Hebrew, Greek, and Vulgate read "in your temple" rather than "people".] Who have received, and where have they received? Is it not the people itself that has received mercy? If your people has received mercy, how have we received mercy, and in the midst of your people, as though distinct persons: those who have received, and those in whose midst they have received? … All who bear God's sacraments are counted as God's people, but not all reach his mercy. All who receive the sacrament of Christ's baptism are called Christians, but not all live worthily of that sacrament. For there are some of whom the Apostle says: they have the appearance of piety, but deny its power.
He lives worthily of God's mercy, who hears and holds and does what the Apostle says: "we warn and entreat you not to accept the grace of God in vain" (2 Cor 6:1). Therefore he who has not received the grace of God in vain, has received both the sacrament and the mercy of God.
"We have received your mercy, God, in the midst of your people." In the midst of your people who do not receive mercy we have received your mercy. "He came into his own, and his own did not receive him. But as many as received him, he gave power to become children of God."
At this point a question will occur to anyone thinking about the matter: That people who in the midst of God's people have received God's mercy, how great a number will it be? How few they are! Scarcely anyone such is found; can it be that God will be displeased with all the rest, and destroy so great a multitude? They tell this to themselves, promising themselves what they have not heard God promise. And indeed if we should live wickedly, if we immerse ourselves in enjoying the delights of this world, if we are slaves to our lusts, will God destroy us? For how many are there who keep God's commandments? We hardly find one or two, at any rate very few; will God save those alone, and damn the rest? "By no means!" they say. "When he comes and sees such a great multitude at his left hand, he will have mercy, and will grant indulgence."
Evidently the serpent also promised this to the first man; for God had threatened death, if he tasted of the fruit, whereas the serpent said: by no means, you will not die the death. They believed the serpent, they found God's threat to be true, the devil's promise to be false. So also now, brethren, put the Church before your eyes. See how it is an image and likeness of Paradise: the serpent does not cease to suggest what he then suggested. But the experience of the first man's fall should avail to warn us not to imitate his sin. He fell so that we might rise. Let us answer such suggestions the way Job did. For the devil tempted him through a woman, as through Eve, and, overcome in paradise, he overcame in the dung. Therefore let us not listen to such words, nor let us think that those [who keep God's commandments] are few; they are many, but they are hidden among an even greater number. For we cannot deny that the wicked are many, and so many that the good are not apparent among them, as a seed is not apparent on the threshing floor. For whoever sees the threshing floor can think that the chaff is alone. Send an inexperienced man, and he will foolishly think that oxen are sent and man sweat there in the heat in order to crush the chaff; but there is in fact a mass to be purged by exposure to the wind. Then an abundance of grain appears, which was hidden in the abundance of chaff. And now you want to find those who are good? Be such, and you will find them. Therefore against that despair see what follows in the psalm. For when the psalmist had said: "we have received your mercy, God, in the midst of your people," he indicated that that people, in the midst of which some receive God's mercy, was not receiving God's mercy; and lest men should get the idea that they are so few as to be almost none, how he has consoled them with the following words? "As is your name, God, so is your praise unto the ends of the earth." (St. Augustine, Commentary on Psalm 47 (48))
The argument "How many are there who keep God's commandments? We hardly find one or two, at any rate very few; will God save those alone, and damn the rest? By no means! When he comes at sees such a great multitude at his left hand, he will have mercy, and will grant indulgence." is not altogether implausible in view of the fact that eternal punishments are threatened in order to restrain persons from doing evil and thus lead them to God. If the obligation of the commandments, the breaking of which is punished by hell, were to have as a consequence that more people were ultimately separated from God than would have been in the absence of those commandments and threats, then the commandments and the threat of hell would seem to be counterproductive, something for which God would not have a motivation.
Augustine does not directly address the plausibility of this argument. One, could, however, answer it in several ways: (1) in fact many persons are restrained from evil and begin the path to good by reason of the fear of hell; Augustine's answer goes somewhat in this direction, inasmuch as he says that there are many persons will be saved, they are just many less than those who will be damned; (2) the obligation of the commandments and threat of hell does not imply that anyone will go to hell (be separated from God) who would not have in the absence of the commandments, but only makes explicit the separation from God that is already attendant upon a will that bears nothing but hatred for God and goodness; this view seem to be suggested by Pope Benedict's portrayal of hell in Spe Salvi: "There can be people who have totally destroyed their desire for truth and readiness to love, people for whom everything has become a lie, people who have lived for hatred and have suppressed all love within themselves…. In such people all would be beyond remedy and the destruction of good would be irrevocable: this is what we mean by the word Hell." In this description of hell, it seems no one would ultimately go to hell for failing to meet a high standard of love, but for utter depravity, a possibility of separation from the ultimate good, God, that would have equally existed had the commandments and threat of hell not been explicated.