Why is it that baptism is not required of some (mental deformities, children who die before the age of accountability, etc) when Christ was baptized “to fulfill all righteousness”? Won’t they need to be baptized at some point to inherit Celestial Glory?
Baptism into the kingdom is a baptism of repentance. Those who are incapable of repentance have no need of baptism. The great atoning sacrifice of the Savior has paid the full price of all their sins, since they are incapable of being responsible for their own actions. The Savior allowed Himself to be baptized, not because he had anything to repent of, but in order to fulfill the law of the gospel, since baptism is also the sign of a covenant to take upon oneself the name of Jesus Christ, to obey the Father’s commandments and to remain true and faithful all the days of one’s life.