Here are some things about the mandate for Christ-centered preaching that I have learned from others.
Our Lord Jesus and His Apostles were masters of Christ-centered preaching. Every word our Lord uttered was ultimately about His person and work as our Prophet, Priest, and King, especially when He expounded Old Testament texts. The Apostles followed their Master’s example in this regard. Every evangelistic sermon and every epistle was ultimately centered on Jesus Christ, His Person and work, applied to sinner and saint alike. In every application to the Christian’s life, there was somewhere a Christ-centered basis for that application, which was always related to His Person and work. I am not saying that Jesus Christ was mentioned by name in every text of His preaching and the Apostles’ teaching. I am saying that who He is and what He has done permeates all Christian proclamation. So, is there a biblical mandate to preach Christ in all the Scriptures? Is the pastoral preacher and expositor required to preach Christ?
The Mandate in Evangelistic Preaching
First, it is clear that the Apostles preached Jesus Christ as Lord and Savior to the unconverted (Acts 5:42, 8:35, 11:20). He was the center of their message. When Paul first came to Corinth, he preached Christ.
1 Corinthians 2:2, “For I determined to know nothing among you except Jesus Christ, and Him crucified.”
Jesus Christ, the only Mediator between God and man, His Person and work, was the subject matter of Paul's evangelistic preaching in Corinth. The same can be seen of Peter on the day of Pentecost and in the other evangelistic messages of Acts (Acts 2; 10; 17).
The Mandate in Pastoral Preaching to Christians
The Apostles did not merely preach Christ in His Person and work to the unconverted. They also preached Jesus Christ to Christians, tying their rebukes, exhortations and doctrinal instructions to the person and work of Christ-- past, present, and future. It is impossible to read the Epistles, which were to be read in their entirety to the churches (and thus were sermonic) without seeing that the Person and work of Jesus Christ is both the power of justification and also the center of sanctification. The letter to the Hebrews is commonly accepted as an example of preaching to Christians.
To the Colossians, Paul described the content of his preaching and teaching to Christians: Colossians 1:28, “We proclaim Him, admonishing every man and teaching every man with all wisdom, so that we may present every man complete in Christ.”
John began his first epistle to Christians: 1 John 1:3, “What we have seen and heard we proclaim to you also, so that you too may have fellowship with us; and indeed our fellowship is with the Father, and with His Son Jesus Christ.”
Paul also tied his exhortations to the Corinthian Christians to the Person and work of Christ. For instance, when warning against adultery, Paul said: 1 Corinthians 6:19-20, “Or do you not know that your body is a temple of the Holy Spirit who is in you, whom you have from God, and that you are not your own? For you have been bought with a price: therefore glorify God in your body.”
In 1 Corinthians 15, Paul encouraged Christians in their daily work with the resurrection of Christ and its promise of His glorious return: 1 Corinthians 15:57-58, “But thanks be to God, who gives us the victory through our Lord Jesus Christ. Therefore, my beloved brethren, be steadfast, immovable, always abounding in the work of the Lord, knowing that your toil is not in vain in the Lord.”
Thus, the Apostolic preaching to both the unconverted and to the converted, was proclaiming Christ to make every man complete in Him. That is the biblical mandate to preach Christ in His Person and Work both to unbeliever and believer.
But is there a biblical mandate to preach Christ in every sermon from every text? There is:
Ever since Gen. 3:15, Jesus Christ, the Savior, has been the centerpiece of God's revelation. Adam represented us and fell into sin, breaking God's covenant of works, which required perfect obedience unto life. Now, Jesus Christ, the last Adam, is the only Mediator between God and man. He is the only Savior of sinners. The entire OT points forward to His coming by way of promise and anticipation, and the entire NT is the revelation of His coming to fulfill that promise. The New Testament explains how the OT is fulfilled in Jesus Christ. Therefore, just as He is the focus of God's biblical revelation, so also must He be the focus of our biblical preaching.
Sometimes, in the rediscovery of biblical truth and the Reformed faith of our Baptist forefathers, we hear phrases like this: "The central truth of all Scripture is the sovereignty of God over all things" or "the central truth of all Scripture is the glory of God." Sometimes we hear sermons and read books glorifying the sovereignty and glory of God. But, if we wish to glorify God Himself, then we must glorify God in His perfect self-revelation, which is the person of Jesus Christ. Jesus Christ and Him crucified, risen, reigning and coming must be our emphasis to the glory of the Triune God. His person and work must be the focus of all our preaching because God Himself must be the focus of all our preaching.
The center of Scripture in revealing the Godhead’s glory and sovereignty to man is Jesus Christ, His person and work as Creator, Redeemer, and Judge. Jesus Christ is the Father’s representative in carrying out these functions. There is a biblical-theological mandate to preach Christ in all the Scriptures because both the OT and the NT are theologically centered in Jesus Christ.