“In the past,” wrote the author of Hebrews, “God spoke to our forefathers through the prophets at many times and in various ways. But in these last days He has spoken to us by His Son, whom He appointed heir of all things, and through whom He made the universe” [Heb. 1:1-2]. The God who reveals Himself (Deus Revelatus) has spoken supremely and definitively through His Son.

Carl F. H. Henry once stated that only a theology based in a vision of “divine invasion” could lay claim upon the church. The same holds true for a theology of preaching. All Christian preaching is unabashedly Christological.

Christian preaching points to the incarnation of God in Christ as the stackpole of truth and the core of Christian confession. “God was in Christ, reconciling the world unto Himself” [2 Cor. 5:19]. Thus, preaching is itself an act of grace, making clear God’s initiative toward us in Christ. Preaching is one means by which the redeemed bear witness to the Son who saves. That message of divine salvation, the unmerited act of God in Christ, is the criterion by which all preaching is to be judged.

With this in mind, all preaching is understood to be rooted in the incarnation. As the apostle John declared, God spoke to us by means of His Son, the Word, and that Word was made flesh and dwelt among us [1:14]. All human speech is rendered mute by the incarnate Word of God. Yet, at the same time, the incarnation allows us to speak of God in the terms He has set for Himself–in the identity of Jesus the Christ.

Preaching is itself incarnational. In the preaching event a human being stands before a congregation of fellow humans to speak the most audacious words ever encountered or uttered by the human species: God has made Himself known in His Son, through whom He has also made provision for salvation.

As Karl Barth insisted, all preaching must have a thrust. The thrust cannot come from the energy, earnestness, or even the conviction of the preacher. “The sermon,” asserted Barth, “takes its thrust when it begins: The Word became flesh…once and for all, and when account of this is taken in every thought.” The power of the sermon does not lie in the domain of the preacher, but in the providence of God. Preaching does not demonstrate the power of the human instrument, but of the biblical message of God’s words and deeds. Barth’s theology falls short of biblical orthodoxy, but on this point, he understands the character of true preaching.

Jesus serves as our model, as well as the content of our preaching. As Mark recorded in his gospel, “Jesus came preaching” [1:4], and His model of preaching as the unflinching forth-telling of God’s gracious salvation is the ultimate standard by which all human preaching is to be judged. Jesus Himself sent His disciples out to preach repentance [Mark 6:12]. The church received its charge to “preach the good news to all creation” [Mark 15:15]. Preaching is, as Christ made clear, an extension of his own will and work. The church preaches because it has been commanded to do so.

If preaching takes its ground and derives its power from God’s revelation in the Son, then the cross looms as the paramount symbol and event of Christian proclamation. “We preach not ourselves,” pressed Paul, “but Jesus Christ as Lord” [2 Cor. 4:5]. That message was centered on the cross as the definitive criterion of preaching. Paul understood that the cross is simultaneously the most divisive and the most unifying event in human history. The preaching of the cross–the proclamation of the substitutionary atonement wrought by the sinless Son of God–”is foolishness to those who are perishing, but to those of us who are being saved, it is the power of God” [1 Cor. 1:18].

Any honest and faithful theology of preaching must acknowledge that charges of foolishness are not incidental to the homiletical task. They are central. Those seeking worldly wisdom or secret signs will be frustrated with what we preach, for the cross is the abolition of both. The Christian preacher dares not speak a message which will appeal to the sign-seeker and wisdom-lovers, “lest the cross of Christ be emptied of its power” [1 Cor. 1:17]. As James Denney stated plainly, “No man can give at once the impression that he himself is clever and that Jesus Christ is mighty to save.”

Beyond this, Paul indicated the danger of ideological temptations and the allure of “technique” as threats to the preaching of the gospel. Writing to the church at Corinth, Paul explained: “My message and my preaching were not with wise and persuasive words, but with a demonstration of the Spirit’s power, so that your faith might not rest on men’s wisdom, but on God’s power” [1 Cor. 2:4-5].

To preach the gospel of the Son who saves is to forfeit all claim or aim to make communication technique or human persuasion the measure of homiletical effectiveness. Preaching is effective when it is faithful. The effect is in the hands of God.

The preacher dares to speak for God, on the basis of what God has spoken concerning Himself and His ways, and that means speaking the word of the cross. That underscores the humility of preaching. As John Piper suggests, the act of preaching is “both a past event of substitution and a present event of execution.” Only the redeemed, those who know the cross as the power and wisdom of God, understand the glory and the burden of preaching. To the world of unbelief, such words are senseless prattle.

To preach the message of the Son who saves is to spread the world’s most hopeful message. All Christian preaching is resurrection preaching. A theology of preaching includes both a “theology of the cross” and a “theology of glory.” The glory is not the possession of the church, much less the preacher, but of God Himself.

The cross brings the eclipse of all human pretensions and enlightenment, but the empty tomb reveals the radiant sunrise of God’s personal glory. If Christ has not been raised, asserted Paul, “our preaching is useless” [1 Cor. 15:14]. This glimpse of God’s glory does not afford the church or the preacher a sense of triumphalism or self-sufficiency. To the contrary, it points to the sufficiency of God and to the glory only he enjoys–a glory He has shared with us in the person and work of Jesus Christ. The reflection of that revelation is the radiance and glory of preaching.