Why can anyone administer baptism?
I don't understand why the faithful are allowed to baptize one another. What makes this sacrament different from the others that an ordained priest does not have to administer it?
The ordinary ministers of baptism (in other words, the people ordinarily expected to perform baptism) are priests and deacons. Because baptism is ordinarily necessary for salvation (John 3:5; CCC 1257), in life-and-death situations in which a priest or deacon is not available, anyone—including Catholics, non-Catholics, non-Christians, and non-theists—may baptize so long as they do so in the correct manner and with the correct intention (to baptize).