There are long traditions for both infant and older-age baptism that spring from different beliefs about original sin and saving grace. People who do it can point to Biblical passages about believers and their children coming to Christ; people who don't do it can point to passages about coming to Christ and declaring faith. The point is, though, they all do it at some time.

For a lot of churches -- and not just Catholics by any means -- infant baptism confers God's grace, welcomes the baby into the faith community, and washes away original sin, depending on the particular church.

You know, nobody really believes that baptism removes all sins anyway. Groups like Catholics will continue to declare sins and receive assurance of forgiveness. Groups like Baptists focus solely on God's saving grace and don't seem to call for much accounting about adult sin. It just depends on how you look at it.