We tend to think of "sacraments" as the two sacraments we celebrate in the church today: baptism and the Lord's Supper. But God has always communicated with his people "sacramentally." By that we mean that God has always used physical things from the world he made as special signs to assure us of his grace and presence, and to mark the special events that display his salvation. Broadly speaking, sacraments are physical things that convey God's grace and truth to us.

Already in the story of the Garden of Eden we see "sacramental" objects. The "tree of life" and the "tree of the knowledge of good and evil" mark the boundaries of life with God. A few chapters later, God sets the rainbow in the sky and says, "This is the sign of the covenant I have established between me and all life on the earth" (Gen. 9:17). Further on, God gives Abraham the covenant sign of circumcision, and when God delivers the Israelites from Egypt, he establishes the Passover as a sacramental sign to remind the people of his liberating grace.

In the passage for today, Joshua leads the people into the promised land by crossing the Jordan River. Afterward, God directs them to build a pile of rocks in the Jordan; one stone for each tribe of Israel "to serve as a sign among you" (Josh. 4:6). Notice how God explains the way this sign is to work: when children of future generations ask "What do these stones mean?" their parents are to tell them the story of their deliverance.

But these sacramental signs are more than mere reminders of past events. They are meant to awaken and strengthen faith in the God who delivers us. In other words, they are intended to help us not only remember the past, but to believe in the future. They not only remind us of God's past actions; they assure us of God's continuing power and grace in our lives.

So it's no surprise that God gives us sacraments as a sign of our salvation through the death and resurrection of Jesus Christ. Baptism is the sign of our belonging to Christ. In the New Testament, Peter and others relate this sign to Israel's passage through the water of the Red Sea, by which God delivered his people and made them his own. The Lord's Supper was inaugurated as the Passover meal, and forever after it has become the Christian Passover. Christ, our Passover, has been sacrificed for us; therefore let us keep the feast (see 1 Cor. 5:7-8).

Again, it's important that we see these new covenant sacraments not as mere occasions to remember the events of Christ's death and resurrection. They are what the Reformers called "means of grace": through them God assures us of the grace he gives to us through Jesus Christ. In the words of an old form for communion, in them we are called to "remember and believe."

It's fitting, then, that in worship services the sacraments are deeply connected with the preaching of the Word. Both baptism and the Lord's Supper remind and assure us that we belong to God and have received his forgiveness in Jesus Christ. We don't believe in the sacraments, but we certainly believe through them.