Geerhardus Vos, in a sermon preached at Princeton in 1902, notes the importance of constant and clear gospel-centered preaching and how it relates to the celebration of Holy Communion.
“There can be a betrayal of the gospel of grace by silence. There can be disloyalty to Christ by omission as well as by positive offence against the message that he has entrusted to our keeping. It is possible, Sabbath after Sabbath and year after year, to preach things of which none can say that they are untrue and none can deny that in their proper place and time they may be important, and yet to forego telling people plainly and to forego giving them the distinct impression that they need forgiveness and salvation from sin through the cross of Christ.”
He continues by saying that each sermon doesn’t need to be what we call evangelistic. Yet “whatever topic you preach on and whatever text you choose, there ought not to be in your whole repertoire a single sermon in which from beginning to end you do not convey to your hearers the impression that it is impossible for you to impart to them what you want other than as a correlate and consequence of the eternal salvation of your souls through the blood of Christ, because in your own conviction that alone is the remedy which you can honestly offer to a sinful world.” In other words, the people in the pews need to see and hear that a preacher cannot but preach the gospel, even when other important truths are being expounded.
So how does a preacher know if he is gospel centered or not? “A good test to apply is the frequent comparison of the purport of your sermon with the purport of the sacrament. The word and the sacrament as means of grace belong together: they are two sides of the same divinely instituted instrumentality.” The central message of the preached word should clearly agree with the central message of the visible word: the torn body and poured out blood of Jesus for forgiveness of sin.
“Let us therefore be careful to key our preaching to such a note that when we stand as ministrants behind the table of our Lord to distribute the bread of life, our congregation shall feel that what we are doing then is only the sum and culmination of what we have been doing every Sabbath from the pulpit.”
When the pastor preaches the gospel constantly and clearly, the Lord’s Supper is rightly an echo of the preaching. Or, stated differently, the Lord’s Supper is God’s “Amen” to gospel preaching.