This is a relief of a piece of ancient Roman graffiti mocking the Christian's devotion to a crucified God. It reads, "Alexamenos worships his god." The god is here depicted as a jackass. "We preach Christ crucified...foolishness to Gentiles."
In 1Corinthians 1:18-2:5, Paul makes the case against his critics in Corinth (as well as his “fans,” who have too closely attached themselves to his ministry, 1:12-16) for preaching an ‘elementary’ gospel, stripped of any of the intellectual trappings of philosophical sophistication, rhetorical deftness, and polished speech (1Co.2:1-4; cf. 2Co.10:10; 11:16) - all designed to impress…all designed to persuade by appealing to, and thereby affriming, the world’s pretense of knowledge and power. Paul states that such preaching would in fact make the message of the cross “void,” emptied of its power.
Why?
He gives two reasons, essentially. First, God has exposed the wisdom and power of the world as folly and, therefore, as weakness. God's wisdom and power, unveiled in the cross, has undermined the world's. To appeal to it, therefore, would be backward and, ultimately, at odds with the divine power of the cross.
Sir Francis Bacon famously wrote that knowledge is power. But Frederich Nietzsche profoundly altered the innocent connection between the two by asserting that all “knowledge” is in fact the construct of power. Truth claims, he argued, are power-plays, promoting those who advance these claims, while marginalizing those who oppose them, or otherwise fall outside the scope of their interest. Thus “knowledge is power” takes on a new, darker nuance. Michel Foucault, following Nietzsche’s geneaology of morals, etc., not only sought to betray the social construction of Western ‘normativity’ in various arenas, but ‘deconstructed’ them as arbitrary, and ultimately, as strategies of power, self-serving (‘self’ here refers, by and large, to the bourgeois middle class). Of course, his own agenda, as the “archaelogist of knowledge,” was equally self-serving - what else could it be?
God is the utlimate deconstructor of human wisdom, knowledge and power. And his agenda, unlike ours, is both self-serving and just. It is just, as John Piper has well argued in numerous places, precisely because it is God-serving - serving the purposes and ends of omnibenevolence in righteousness and truth. But this ‘truism’ hits home when we understand, through the message of the cross, that at the center of God’s self-serving agenda against and for the world stands the divine self-giving of Christ crucified.
What do we mean when we say that God has deconstructed the world in its wisdom and power? We mean that He has exposed it’s failure, in judgment, and condemned it, all at once in the 'apocalyptic' revelation of the mystery of God (cf. 2:1,7). Namely, God was well-pleased to show up its pretention through the foolishness and weakness of the gospel. “For since in God’s wisdom the world through its wisdom did not come to know God, it pleased God through the folly of what was preached to save those who believe.” It is God’s wisdom that the world, in its wisdom, should fail to come to a true knowledge of God. Why? Simply this: so that no man might boast (1:29, 31).
Not only is the incomprehensible and invisible God known only through His sovereign self-disclosure, but, even given this, sinful man cannot come to know God through the lens of his loaded, epistemic constructs - driven, as they are, by his own “will to power.” God will not be found by the self-seeking. More than that, fallen man’s wisdom is grounded in a godless hubris; in his pretentious wisdom and power, he exalts himself! If a sinner found God through his own wisdom, we might never hear the end of it. Hence, God is not only inscrutible to the proud, by the very nature of His holiness, but, morally, volitionally, as ruler and judge, refuses them this boast.
That’s why. But how?
Specifically, God exposes the world’s failure in publically presenting a crucified Messiah to the world, only to to be rejected. The Jew rejects it as the “anti-miracle,” to borrow from Eugene Peterson’s paraphrase, and the Greek rejects it as utter non-sense. So the world, as represented by the ‘wise’ and ‘powerful’, has rejected the very wisdom and power of God, and thereby shown itself entirely foolish and (morally) incompetent. God's folly deconstructs the world's wisdom. (In other words, God clearly presented the truth in a way which did NOT appeal to the world’s values - for its values were morally corrupt and self-absorbed - and thus, through their condemnation of the Truth, damned the world’s system of evaluation.)
Surely the wisdom of the Jewish scribes was exposed in their rejection of the long-awaited Messiah, to whom all the Scriptures had pointed. So much for their biblical expertise and wisdom! Surely the power the Saduccees, Herodians and Romans wielded in arresting, condemning and executing the Lord of glory was unveiled as not only child’s play, but as britches far too big for their slender frame, by the resurrection of the sovereign Christ. So much for the imposing power of the rulers of this age! Even as we speak, their authority evaporates (2:6).
And this continues, of course, in Paul’s ministry, as both Jew and Gentile reject Paul’s gospel as foolish, as weakness - as the detestable stench of death (2Co.2:14-16 1Co.1:18). It continues to this day, whenever the world rejects Jesus, while standing on the ground of its own wisdom and power. God has already pulled the rug out - and in rejecting the gospel, they come crashing down upon the same, hard ground. As it was written, they have stumbled over the stumbling block, the stone of offense, which God has placed in Israel. How the mighty have fallen!
“Where is the sage? Where is the scribe? Where’s the critic of this age?” God has made them obselete through the cross. He has nullified them once and for all; and that in which they gloried is now shown to be their shame. God has shot through the world’s show of wisdom and power with its own gun - or in this case, its own gibbet, and put it on display for all to see: Here hangs the wisdom and power of this age!
To apply this to our ‘postmodern’ context, we might add, “Where is the tolerant inclusivist of our age?” Has not God shown up our pretense of tolerance and inclusion? For the world, in all of its talk of inclusivity, still excludes Jesus (on His own terms)! The world excludes its maker, its sustainer and redeemer! In its violent intolerance of God’s Word, the very light of the world - marginalizing God's truth in Christ, and seeking (in vain) to extinguish His brilliance (Jn.1:5) - God has uncovered the hypocrisy, bankruptcy and tragic failure of its inclusive rhetoric. And, as men, women, and children from every tribe, language, people-group and religion come to Christ, God’s exclusivity is proved daily more inclusive than all the world’s inclusivity!
As Christians we shouldn’t be postmodern, but post-‘flesh’, post-history, post-everything this side of heaven. We ought rather to be sages, scribes and scholars of the age to come.
To then preach in such a way as to appeal to the world’s pretense of knowledge and power is to employ a strategy deconstructed by the gospel itself. More than that, it is to frame the cross, which signifies the world’s judgment, as though it were its reward. The medium violently contradicts the message.
The world, with its rhetoric, manipulates with selfish or political intent. The preacher of the gospel, however, rather than impress and manipulate according to his own agenda, ought to align himself with God's agenda (requiring repentance), with the self-emptying gospel he proclaims (requiring love) - speaking plainly, sincerely, even pouring out his life for his hearers, and so, like the apostle, embodying the self-giving of Christ crucified (cf. 1Co.4:9-13; 2Co.4:7-16).
The second reason Paul articulates is that, if we do persuade our audience through appeal to the world’s values, rather than to the cross alone, than the confidence in the power of Christ crucified is eroded. We feel our conversion might rest on man’s wisdom, rather than God’s (2:5).
Human arrogance is so pernicious and pervasive, that even the newly born Christian is tempted to boast that their new-found faith - their newly acquired spiritual understanding and power - is somehow to their credit. As though we who believe do so because we had a superior knowledge or strength! But Paul makes plain that it is the power of the cross, at work as God Himself calls us into fellowship with His Son (1:30-31; 1:9), which is the source of our new life. Paul here reminds the very status-conscious Corinthians of their unimpressive past - their not-so-glorious former ‘group identities’ (1:26-29) - in underlining God’s sovereignty and goodness in calling them, as part of the divine undermining of the world’s values (transvaluation). Their salvation rests neither on the brilliance of the preacher, nor upon their own brilliance in discerning it (if anything, quite despite it), but upon the cross of a crucified Messiah - the foolishness and weakness of God!
And this basis is infinitely more superior than grounding our confidence in our own wisdom or power. As Paul states, God’s foolishness is greater than any man’s wisdom, and His weakness is stronger than any man’s power. It is this dumb and servile Christ who establishes our confidence of faith, and our new status in Him (1:30b); it is in this Jesus that we boast! And all the world shall never hear the end of it!

