We have considered what our confession of faith states about the Lord’s Supper specifically, but we can also be blessed by thinking through the biblical basis for the claims it makes about sacraments generally.
First, what are the sacraments? Of course there are two of them—baptism and the Lord’s Supper. And because they share the common name of sacrament, they must also share certain characteristics. The Confession says that both of them are signs and seals of the covenant of grace.
Now the covenant is actually made with all worthy receivers—and worth is defined in terms of faith, not in terms of any kind of self-righteous works. Stated short-hand the covenant is efficaciously made, for blessing, with the elect.
But it does not follow from this that the covenant is invisible, just like the entire body of the elect is invisible. No, the covenant, the terms of it, and the signs and seals of it, are all visible—they are all right here. The word we preach, the gospel we preach, is declared in real time. The water that we baptize with is real water. The wine and bread we consecrate is earthly bread, baked in an oven, and the wine is earthly wine, fashioned by human artifice from the juice of grapes. These are not similitudes for the covenant of grace; they are rather manifestations of the covenant of grace.
Those who have true faith respond to these signs and seals, and are therefore brought to the reality behind them. They are not the ones who bypass the means, on their own going straight to the reality behind them. There are no shortcuts here.
You must travel the road that God has built for you. You will only do so if you believe in Him, trusting Him to keep His promises. But trusting Him to keep the promises He made through Word, Water, and Wine is not the same thing as claiming that He has made no promises in and through such things at all. You must walk, by faith alone, in the way He established. As you do, you will see more and more clearly.
The covenant of grace is made with all the elect, and the extent of that body does not yet appear. There is a good bit of history yet to go, and the ranks of our numbers have a good deal of filling up to do. But those ranks will fill up here, in this world, by the means that God has established. It makes sense to say that the number of the decretally elect belongs to the secret things. But it is unbelief to say that the covenant of grace is secret. Do not say in your heart, who will go up to heaven to get it for us, or who will cross the sea for it. No, the word, the gospel, the covenant, is in your mouth and in your heart. Here, today, and forever.