Because the foolishness of God is wiser than men; and the weakness of God is stronger than men.
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When Paul speaks of the “foolishness of God,” he is not implying that God is foolish. Rather he is saying that since God’s way of reasoning is in accord with things of the spirit, it confounds the reasoning of this world. It is wiser than human reasoning, because spiritual things are wiser than carnal ones. Spiritual things do not exist through carnal ones, but the other way around. Therefore carnal things are understandable in relation to spiritual ones. Similarly, what belongs to heaven is stronger than what belongs to earth. So what seems like the weakness of God is not really weak at all. Christ appeared to be defeated when he was killed, but he emerged as the victor and turned the reproof back on his persecutors. Commentary on Paul’s Epistles.
There is no way that this gospel truth could have been made acceptable to some philosophers and debaters. They follow a way of life that does not stand in the truth but is only an imitation of it. They deceived themselves and others. Letter , To Consentius.
Because the foolishness of God is wiser than men, and the weakness of God is stronger than men. That Isaiah , say Ambrose and Anselm, the foolishness and weakness of God, or what men think is the foolishness and weakness in God and in Christ incarnate and suffering, as e.g, His humanity, morality, Passion and Cross, was just that by which Christ, when seemingly conquered, yet most wisely and most powerfully conquered men, Satan, and the whole world. In other words, God"s wisdom and strength by what was foolish and weak, viz, the Cross. And therefore Jerome and S. Augustine explain the passage of Habakkuk (iii4) "He had horns coming out of His hands," thus: The strength and weapons by which, as by horns, Christ slew His foes were the arms of the Cross to which the hands of Christ ere nailed. Hence it is that the cross in the sky appeared to Constantine the Great as he was going to battle against Maxentius, with the inscription, "In this sign thou shalt conquer" (Euseb, Life of Constanti...
The folly and the wisdom spoken of here are more apparent than real. For the philosophers could not achieve what a few unlearned men accomplished, namely, the conversion of the whole world. The philosophers spoke about trivialities and convinced only a few. The apostles spoke about God, righteousness and judgment and converted a great many.
6. All these things, therefore, Paul bearing in mind, and being struck with astonishment, said that the foolishness of God is wiser than men, and the weakness of God is stronger than men; in relation to the Cross, speaking of a folly and weakness, not real but apparent. For he is answering with respect unto the other party's opinion. For that which philosophers were not able by means of reasoning to accomplish, this, what seemed to be foolishness did excellently well. Which then is the wiser, he that persuades the many, or he that persuades few, or rather no one? He who persuades concerning the greatest points, or about matters which are nothing? (μηδὲν όντων Reg. ms. μη δεόντων Bened.) What great labors did Plato endure, and his followers, discoursing to us about a line, and an angle, and a point, and about numbers even and odd, and equal unto one another and unequal, and such-like spiderwebs; (for indeed those webs are not more useless to man's life than were these subjects;) and wit...
We, however, know that "the foolishness of God is wiser than men, and the weakness of God is stronger than men.".
Now, what is that "foolishness of God which is wiser than men "but the cross and death of Christ? What is that "weakness of God which is stronger than men"