In verse 18 Paul declares that the preaching of the gospel of Christ is foolishness to natural men. The mysteries of grace are hidden from the wise and prudent (Matt. 11:25; 1 Cor. 2:7, 8). So it is nothing unusual for men who are distinguished for wisdom in other areas to reject totally and despise the gospel of redemption.
(Vs. 19.) In a quotation from Isaiah 29:14, Paul shows how unreasonable it is to question the gospel of the cross on the ground that the so-called wise men of the world call it foolishness. God says, 'I will render useless their wisdom, learning and philosophy.' Men who are wise in their own esteem become fools, men who profess to see by the light of human wisdom are struck blind and the wisdom of this world becomes vain and worthless when it exalts itself against God (2 Thess. 2:10-12; 1 Cor. 3:18).
(Vs. 20.) Where is the wise man, who boasts of his superior wisdom and knowledge? Where are the scribe and the scholar? Where is the debater and disputer of this world, who derives his wisdom, not from the Holy Spirit, but from human understanding? They are not to be found among those whom the Lord uses to minister the gospel, to write the Scriptures, or to load his church. Without Christ all sciences are vain, all roads lead to ruin and all human wisdom is foolishness. The gospel exposes all worldly wisdom to be what it is – foolishness (Rom. 1:18-24).
(Vs. 21.) When the world (with all of its earthly wisdom) failed to recognize and know the living God by means of its own God (in his wisdom and purpose) was pleased to reveal himself and his salvation (purchased and provided by Christ) through the very means the world calls foolishness - preaching of the gospel! While the wise men of the world left to perish in their sins (ignorant of God), the gospel they despise has become the power of God unto salvation to all that believe in Christ (Rom. 1:14-17).
(Vs. 22.) The Jews required a sign from heaven that Christ is the Messiah. Though miracles were wrought and Scriptures fulfilled, they required their own signs in their own way. The Greeks (those distinguished by superior intelligence) seek after that which satisfies human intellect.
(Vs.23.) We preach a crucified Christ, bearing our sins in his body on the tree, forsaken of God and rejected of men. To the Jew this message is a scandal and an offensive stumbling-block, and to the Greek it is sheer nonsense and absurd.
(Vs. 24, 25.) But to those who are called, enlightened and of God, Christ crucified is not only 'the power of God' to save, but 'the wisdom of God'. We see in Christ the law honoured, justice satisfied and every attribute of God glorified, enabling him to be just and Justifier (Rom. 3:19-26). What men call foolish (if it is of God) is wiser than men, and what men call weakness (if it is of God) is stronger than men.
(Vs. 26-28.) 'Consider your own calling; look about you in the church. Not many of you' (he does not say none of the noble and mighty are called, for some were saved) 'were considered to be wise according to human standards; not many of you were influential, powerful, or of a high and noble birth. But God chose those whom the world calls foolish to put the wise to shame. God chose the weak to put the strong to shame. God deliberately chose the low-born and those branded with contempt, even those looked upon as nothing, that be might bring to nothing the high.'
(Vs. 29.) God's purpose in choosing and calling these is to banish for ever any glorying in the flesh, that no man may attribute his salvation to anything in himself, but wholly to the sovereign grace and good pleasure of God. There is nothing left us in which we may glory in his presence.
(Vs. 30.) It is not of us but totally from God that we are in Christ and that we have life in Christ. Christ is our 'wisdom', revealing to us the mysteries of godliness and spiritual truth. Christ is our righteousness making us upright, and putting us in right standing with God. Christ is our 'sanctification', making us pure, holy and unblameable. Christ is our 'redemption', providing our ransom from the curse and condemnation of sin.
(Vs. 31.) So then it is written: 'He that boasts, rejoices and glories, let him glory only in the Lord!' (Jer. 9:23, 24).