The preaching of the Word is the chief means of grace and that through which God the Spirit creates saving faith among the elect. The function of the sacraments is to confirm saving faith among the elect. The sacraments are divinely ordained means of sanctifying not saving grace. The only divinely ordained sacraments are baptism and the Lord's Supper. The sacraments are God's Word visible.
Scripture teaches the baptism of covenant children.
We do not baptise covenant children on the presumption of their regeneration, but on basis of the divine command and promises attached to baptism. The mode of baptism is morally indifferent though effusion is exegetically and historically preferable since, in the history of salvation, the only ones who were immersed were those who were not on the Ark with Noah and Pharaoh and his armies. Baptism is an identification with Christ and his death, not an identification with the reprobate. By the operation of the Holy Spirit, through faith, Christ feeds believers with his proper and natural body and blood in the Lord's Supper, though he does so by the mystical operation of the Holy Spirit. The system of the catechism is opposed and superior to the system of the anxious bench.