Book 4 of 4 - External Means by which God Invites Us into the Society of Christ and Holds Us Therein
Chapter 16 - Infant Baptism fits with the nature of baptism
17-20 - "Yeah, but infants are incapable of faith"
17. We have to consider children as children of Adam until they can believe, they say. But Jesus called them to Himself because He is life (Matt 19:14); He did not leave them in their death (Rom 5:12ff) until they could believe. "To become heirs of life, we must have communion with Him." "But how, they ask, are infants... regenerated? We reply that god's work, though beyond our understanding, is still not annulled." God gives an example in John the Baptist, set apart from the womb - Luke 1:15. We can't restrict God from doing this, if He chooses.
18. Christ was set apart from infancy, to set apart His people of every age. They object that regeneration is only by God's Word believed - 1 Pet 1:23. But God can regenerate infants by His power "in any way He pleases."
19. But faith comes by hearing, they object. Rom 10:17. This is the normal way God works, yes, but what's the problem with saying infants "receive now some part of that grace which in a little while they shall enjoy to the full?"
20. They object that baptism is unto repentance and faith, which infants don't have yet. They are objecting to God, who gave circumcision as a sign of repentance (Jer 4:4; 9:25; Deut 10:16; 30:6) to infants. "Infants are baptized into future repentance and faith."