If you ask the reason that caused the Greek philosophers to consider themselves wise, the Apostle names it as the hardening of their heart (Eph. 4:18). Since, in the light of the wisdom of God proclaimed by the prophets, and through the wisdom that spoke by the mouths of the wise, the world did not know Him, that is, God, He was pleased to save those who believe through the foolishness of preaching. This means through preaching that seemed foolishness to the Greeks.
For faith, says the Apostle, the Hebrews require miracles, and the Greeks seek wisdom, that is, arguments with strict proofs and other formal conclusions. But we preach Jesus Christ crucified. For the Hebrews He is a stumbling block, because, believing in the prophecies, they do not believe in their fulfillment. For the Greeks He is foolishness, because those who consider themselves wise find it fabulous that the Son of God spoke through the mouth of a man, that God has a Son, and that this Son suffered. Preconceived opinions keep them from believing.
Yet the coming of the Savior did not make those who proved obedient to His call unreasonable, hard-hearted, or faithless. Rather, it formed them into reasonable, obedient, and honorable men. Those who refused to enter into union with these obedient ones, and separated from them, proved by comparison to be unreasonable, faithless, and shortsighted.
But for those who remained faithful to the voice that called them, whether Hebrews or Greeks, Christ is the power of God and the wisdom of God (1 Cor. 1:21-24). With these words the Apostle explains his thought more precisely. Therefore one should not see anything negative toward wisdom in his expression, “Has not God made foolish the wisdom of this world?” Nor should one think that God purposely turned the wise of this world aside and cast them into irrationality.
No, by his expression the Apostle only means that God revealed the irrationality of worldly learning when it is severed from Him. He did this so that no one would consider God Himself the author of the hardheartedness of those who did not believe. The wise of this world were learned enough to be able to believe the evangelical preaching. If they did not believe it, they became only the more responsible. For a man’s inclination toward the truth and his choice of it lie entirely within his will.
Moreover, by the expression, “I will destroy the wisdom of the wise” (Is. 29:14), the Lord was also pleased to express that He poured true light upon it. Alongside Greek philosophy He kindled philosophy also among the barbarians, that is, among the Hebrews. The philosophy of Holy Scripture should here be understood according to the writer’s meaning, not pagan philosophy. Until the most recent time it had been little valued and despised. By this contrast He did what happens to a lamp burning in the sun. Its light is dimmed by the sun, because the strength of its radiance is far inferior to the sun’s.
Since all are called, those who did not refuse obedience to the voice calling them are all alike called “the called” (1 Cor. 1:24). For injustice is not proper to God (cf. Rom. 9:14). Whether they are from the Hebrews or from the Gentiles, if they have believed, they form a particular people, chosen (Tit. 2:14).
In the Acts of the Apostles you will find the expression: “Those who received his word were baptized” (Acts 2:41). Those who did not receive it, therefore, separated themselves from the people of God. To them the prophetic word is addressed: “If you are willing and obedient, you shall eat the good things of the land” (Is. 1:19). This shows that it lies within our power to receive the word of God or reject it.
The Apostle called the teaching of the Lord the wisdom of God, thereby showing us that true philosophy has been handed down to us by the Son of God. For those who count themselves among the wise, the same Apostle’s epistles contain reminders to put on the new man, created according to the likeness of God in the righteousness and holiness of true teaching (Eph. 4:24).
Therefore, having rejected false teaching, the Apostle adds, confess the true teaching. “Give no place to the devil.” “Let him who stole steal no longer, but rather let him labor, doing what is useful.” To seek the truth is to be occupied with a good and useful work. This search for truth is the same as beneficence, except that instead of material substance its instrument is the word.
Thus one may have something to give to him who is in need (Eph. 4:25, 27-28). That is, one may be able to reveal to those in need, and seeking improvement of their condition, both the spiritual riches of this world and also the abundance of wisdom and of divine wisdom.
By commanding that one do what is useful, the Apostle wants true teaching to be studied only through a comparative testing of its worth. In the same way silver is first carefully purified in the furnace, and only afterward given to the moneychangers for increase through interest (Mt. 25:27; cf. Stromata 1, end of chapter 28).
Therefore he adds: “Let no corrupt word proceed out of your mouth” (Eph. 4:29). Such precisely are the words, that is, the teachings, that proceed from human conceit. They are corrupt and repulsive. On the contrary, let everything you say nourish faith and give grace to those who hear (Eph. 4:29).
Since God is good, His word must also be good and trustworthy. And how could these words not be worthy of trust, if they are saving for man?