Acts 2:14-41 is essentially the first Christian sermon in the history of the church. It was preached by the Apostle Peter on the day of Pentecost.
In his sermon, Peter quotes Old Testament passages from Joel as well as the Psalms.
In quoting and interpreting Joel 2:28-32, the Apostle Peter does something remarkable. He quotes a passage where the Hebrew word Yahweh (“LORD” in the English) is used twice and both times attributes that word to Jesus Christ! In other words, he is clearly and unmistakeably saying that Jesus Christ is none other than God Himself!
It should go without saying that by calling Jesus “Lord,” we are acknowledging and confessing that He is none other than God Himself, but in our day that is not always clearly understood. When a Jehovah’s Witness knocks on your door and asks you where the Bible says that Jesus is God, we should be able to quickly point to any of the numerous verses where Jesus is called “Lord” and tell them that from earliest times of the New Testament this has always been the church’s confession of the deity of Jesus Christ.
Jay Adams, who for many years taught homiletics (or preaching) and counseling courses at Westminster Theological Seminary in Philadelphia, as well as teaching some advanced courses at Westminster Seminary California, wrote a very helpful book called, Preaching With Purpose. In it he writes the following:
If you preach a sermon that would be acceptable to the members of a Jewish synagogue or to a Unitarian congregation, there is something radically wrong with it. Preaching, when truly Christian, is distinctive. And what makes it distinctive is the all-pervading presence of a saving and sanctifying Christ. Jesus Christ must be at the heart of every sermon you preach. (p.147)
What is Adams’s point? Jesus’ deity would not be a subject that is acceptable in a Jewish synagogue or a Unitarian church because they would both deny the Trinity, and they would certainly deny the deity of Jesus Christ.
Any sermon, even from the Old Testament, that is not centered on the person and work of Jesus Christ has missed or ignored the primary point of the biblical text. And not only that, but any sermon that focuses on Jesus in the Old Testament that does not make clear who He was and is – the Son of God incarnate – is less than a Christian sermon. It has missed the mark.
So our preaching, in order to be truly biblical, must be Christ-centered. And in order to be truly Christ-centered, the deity of Christ must be clear in our preaching.