On the side of people that practice infant baptism; I do not think it can be properly viewed from the standpoint of "age of reason"(not in NT at all) or "once saved always saved" (debateable - another topic). To try and understand the infant baptism view, it only makes sense within the entire system of beliefs. Think most of the people practicing infant baptism also say as long as that was done properly (not the Mormon way for example) one can only be baptized once. Those Churches will accept baptism from most other Christian Churches. Interestingly within the group of those who say infant baptism is wrong and baptism does nothing for our soul internally there is a smaller subset of that group that in order to be considered "valid" require baptism be conducted within that particular faith (or even that particular Church in some cases- closed membership some call it). Find that interesting because if baptism does nothing for our soul, why would it matter or not whether the particular act for someone is "valid" or not?For that do infant baptism, they consider it a Grace from God that cannot be continually re-applied. You can fall (sin and in some faiths even loose salvation), but once you join the Church, become a Christian (and baptism is a part of that act) one cannot then later re-join the Church - or IOW become a Christian again by being Baptized again. In fact in joining those Churches they will not allow it if they are aware one has already been baptized. From their view, one is or is not already a member of the Church (in this sense a Christian) and a baptism record is a validation of that fact. Of course infant baptism makes no sense if one holds to there being a requirement for an "age of reason" in order to make a single-one-time profession of faith that guarantees salvation. Remove those two more fundamental requirements and infant baptism makes much more sense.When people say that Baptism does nothing internally for us am always curious to know what they think is dsecribed as happening to Jesus when He was Baptized? Also curious to know how they see the difference, as Jesus indicates there is a difference, between what John was doing and what Jesus commanded His diciples to do? If our baptism does nothing at all internally for us, then is the difference that John's baptism actually did something for those he baptised, while the baptism commanded by Jesus does nothing?And when entire households are said to be baptized in the NT, are we to understand those statements as excluding all infants? Or is the assumption that none of the households being referred to had infants? Why would they say "entire" if there were such an exception?