{25} For the Jews require a sign, and the Greeks seek after wisdom:

(25) A declaration of that which he said: that the preaching of the Gospel is foolish. It is foolish, he says, to those whom God has not endued with new light, that is to say, to all men being considered in themselves: for the Jews require miracles, and the Greeks arguments, which they may comprehend by their intellect and wisdom: and therefore they do not believe the Gospel, and also mock it. Nonetheless, in this foolish preaching there is the great power and wisdom of God, but such that only those who are called perceive: God showing most plainly, that even then when mad men think him most foolish, he is far wiser than they are, and that he surmounts all their might and power, when he uses most vile and abject things, as it has appeared in the fruit of the preaching of the Gospel.

People's New Testament

1:22 For the Jews require a sign. Not merely miracles, such as the apostles worked (Ac 4:22 6:08 8:06 15:12 19:11), but a sign from heaven (Mt 16:1 Mr 8:11 Lu 11:16). They said, Let Christ come down from heaven, if he be risen.

And the Greeks seek after wisdom. While the Jews asked for a sign from heaven, the Greeks demanded a well-argued system of philosophy (Ac 17:18).

Wesley's Notes

1:22 For whereas the Jews demand of the apostles, as they did of their Lord, more signs still, after all they have seen already; and the Greeks, or gentiles, seek wisdom - The depths of philosophy, and the charms of eloquence.

Jamieson-Fausset-Brown Bible Commentary

22. For-literally, "Since," seeing that. This verse illustrates how the "preaching" of Christ crucified came to be deemed "foolishness" (1Co 1:21).

a sign-The oldest manuscripts read "signs." The singular was a later correction from Mt 12:38; 16:1; Joh 2:18. The signs the Jews craved for were not mere miracles, but direct tokens from heaven that Jesus was Messiah (Lu 11:16).

Greeks seek . wisdom-namely, a philosophic demonstration of Christianity. Whereas Christ, instead of demonstrative proof, demands faith on the ground of His word, and of a reasonable amount of evidence that the alleged revelation is His word. Christianity begins not with solving intellectual difficulties, but with satisfying the heart that longs for forgiveness. Hence not the refined Greeks, but the theocratic Jews were the chosen organ for propagating revelation. Again, intellectual Athens (Ac 17:18-21, &c.) received the Gospel less readily than commercial Corinth.

Matthew Henry's Concise Commentary

1:17-25 Paul had been bred up in Jewish learning; but the plain preaching of a crucified Jesus, was more powerful than all the oratory and philosophy of the heathen world. This is the sum and substance of the gospel. Christ crucified is the foundation of all our hopes, the fountain of all our joys. And by his death we live. The preaching of salvation for lost sinners by the sufferings and death of the Son of God, if explained and faithfully applied, appears foolishness to those in the way to destruction. The sensual, the covetous, the proud, and ambitious, alike see that the gospel opposes their favourite pursuits. But those who receive the gospel, and are enlightened by the Spirit of God, see more of God's wisdom and power in the doctrine of Christ crucified, than in all his other works. God left a great part of the world to follow the dictates of man's boasted reason, and the event has shown that human wisdom is folly, and is unable to find or retain the knowledge of God as the Creator. It pleased him, by the foolishness of preaching, to save them that believe. By the foolishness of preaching; not by what could justly be called foolish preaching. But the thing preached was foolishness to wordly-wise men. The gospel ever was, and ever will be, foolishness to all in the road to destruction. The message of Christ, plainly delivered, ever has been a sure touchstone by which men may learn what road they are travelling. But the despised doctrine of salvation by faith in a crucified Saviour, God in human nature, purchasing the church with his own blood, to save multitudes, even all that believe, from ignorance, delusion, and vice, has been blessed in every age. And the weakest instruments God uses, are stronger in their effects, than the strongest men can use. Not that there is foolishness or weakness in God, but what men consider as such, overcomes all their admired wisdom and strength.