"Therefore go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit" (Matthew 28:19)
Jesus commanded that all members of the new covenant be baptized with water. What are some of the dimensions of this ordinance or sacrament?
First of all, baptism signifies a person’s entrance into the visible new covenant community - it is a sign of the salvation which has come to the person being baptized. This is why it is so important to hear a person's conversion testimony ahead of applying the sign of baptism. Those who personally profess repentance toward God and faith in and obedience to our Lord Jesus Christ are the only proper subjects of this ordinance (Mark 16:16; Acts 8:36, 37; Acts 2:41; Acts 8:12; Acts 18:8). There are, of course, people who are baptized into the visible church who are not really and finally saved, just as there were people circumcised into Israel who were not faithful to the old covenant, but the pastor must do his best to discern this ahead of the administration of baptism.
Second, baptism is a sign of entrance into the kingdom of God. Baptism puts us into the visible expression of the kingdom (the church), and symbolizes entrance into the invisible fullness of the kingdom. Since only God looks on the heart (1 Samuel 16:7), we should treat each baptized person as part of God’s people unless he gives us strong reason to suspect otherwise.
Third, it is possible for people to be saved and yet not be baptized—though they should be - they really must be. God commands us to join His church. To do that, we must be baptized. But it is possible to enter the kingdom by faith before entering the visible church by baptism. Of course, baptism represents more than just joining the visible church. To those baptized it is a sign of their fellowship with Jesus Christ in his death and resurrection, of their being grafted into him, of remission of sins, and of submitting themselves to God through Jesus Christ to live and walk in newness of life (Romans 6:3–5; Colossians 2:12; Galatians 3:27. Mark 1:4; Acts 22:16. Romans 6:4).
Fourth, baptism represents cleansing. It summarizes all the purification rites of the Old Testament. The reality of cleansing from sin is by the blood of Christ applied to us. This is symbolized by water. Thus, baptism involves a confession of our sinfulness, since only defiled sinners need to be cleansed.
Fifth, water makes us new and clean. Just so, baptism represents (but does not confer) our new birth into the new life in Christ. We are born again by water and the Spirit. Since the Spirit comes down from above (Acts 2), the old covenant baptisms were by sprinkling, not immersion, and the church has usually preferred pouring or sprinkling. We are baptized with the heavenly “waters above,” not into the “waters below” (Genesis 1:6–7).
Finally, cleansing and regeneration are parallel to death and resurrection. Baptism signifies our union with Jesus’ death and our resurrection to a new life in His resurrection. It symbolizes our acceptance of a call to join Christ in His humiliation that we might also join Him in His exaltation.
Read Hebrews 9:13 and 10:22. Now find Numbers 19. Note the relationship between death and resurrection, unclean and clean, and old covenant baptism. What does this chapter teach you about your new covenant baptism? How many times do you need to be baptized with “pure” water?