The New Testament sacraments of baptism and the Lord’s Supper were instituted by God to declare the promise of the gospel tangibly to us and to put God’s own seal on this promise. And what is the promise of the gospel? To forgive our sins and give us eternal life by grace alone because of Christ’s one sacrifice finished on the cross.
In the gospel, God promises to save us from our sins, and in the sacraments he confirms his promise, “I am your God and you are my people”. The emphasis is on what God does for sinners in the person of his son, Jesus, and not on the strength of a sinner’s faith, or the purity of one’s heart. Faith does not make the sacrament. Faith does not create the promise of God. God's promise comes before faith and through faith. Nevertheless, the blessing comes as we by faith receive the sacraments. The sacrament is like the Word preached; it comes with God's promise to all who will receive it. But only those who receive it by faith receive the blessing. The promise of God is there. The promise of God is real. The promise of God is reliable. But for the fruit of that promise to take root in our hearts, we must receive and live in it by faith
The recipients of baptism are believers and their children. Baptism is focused on our initiation into Christ’s visible church. We baptize the children of believers by virtue of their membership in the visible church and covenant people of God. We do not believe in baptismal regeneration [salvation by baptism] or presume that every baptized child is elect. Rather, our children are included with us in the visible church and brought up as disciples in the Christian faith because that has always been God’s design in Scripture. The Lord’s Supper is part of our continuing fellowship as Christ’s church. This explains why it is that before our children are welcomed to the Lord’s Supper they must first profess their faith.
The Lord’s Supper
The Lord's Supper is the Christian Passover. In the Old Testament the Passover looked forward to Christ. In both Passover and Communion, a symbol of Christ is eaten. In both, "remembrance" is central. In both, one eats with, anticipation of the consummation of the one's salvation. Because Jesus inaugurated a "new covenant," (1 Corinthians 11:25), He instituted with it new ordinances appropriate to it. The form is changed, but the central significance is the same. In both, by eating, one participates in the benefits of the Lamb. The Passover was fulfilled by and superseded by the Lord's Table. Holy Communion is the Christian equivalent of the New Passover service where we feed upon a symbol of Christ, participate in His benefits, and anticipate His return. Through it we have the assurance of "eternal life" (Jn. 6:54). Through it we enjoy "true food" (Jn. 6:55). Through it we "abide" in Him (Jn. 6:56) and we celebrate the relationship we now enjoy with God