John as the divinely appointed forerunner of Christ baptized with water. In so doing he signified the glorious fact that there was One coming after him who would baptize with the Spirit. Water was a symbol of the Spirit's work. Baptism with water signifies the sovereign work of God's Spirit as He cleanses, renews, and regenerates the people of God. All that circumcision represented under the Old Testament, baptism represents under the New Testament.
Baptism indicates the foundation of our salvation.
We must be sovereignly and graciously cleansed by God if we are to be made acceptable in His sight. Since we are partakers of the same covenant, since we belong to the same church, and are members of the same kingdom, since there is absolutely no indication that our children have been excluded from the covenant, the children of believers should be given the sign and seal of the New Covenant. Being claimed by God they have a right to the sign and seal of God's covenant. Baptism is the sign of God's sovereign grace in His covenant. It points to His work and His promises and it obligates us to respond faithfully to His love and mercy.