Behind all these statements is your comment on post 185 "infants do not have faith." This is an assumption not found in Scripture. Of course they can have faith....they are SPIRITUAL CREATURES and David, John the Baptist and Jeremiah are examples of regeneration. All of humanity has a spirit which can be regenerated. However, not all are regeneration per John 4.
All life has the capacity to reproduce....remember in Genesis "each according to there own kind.' Infants have the capacity to reproduce, so yes they are complete.
These are the effects of the fall, not the spiritual capacities of infants given to all in creation.
Let's keep the examples to living creatures. You said a infant as a living creature can not have faith. This is what you said. I gave an example of another living creature that de facto can't have faith. Then I made the contrast. It does seem correct that if an infant can not and does not have faith, he truly can be compared to an animal. The comparison ends at the Age of Accountability.
If there is anything know about
Baptist practices of church membership & baptism, they baptize only on a "credible" profession of faith. SMI individuals cannot make this profession, so no baptism and they are not members of the church....hence no Lord's Supper. Severely mentally ill do go to church within a baptist setting but no church membership.
Both John Macarthur and John Piper (
Believer Baptism and Mental Disabilities) are on the record for not baptizing mentally ill and as many many many many commentors here at CF.