Moroni 8 is a letter Moroni received from his father, Mormon. It clarifies the issue of baptism for little children.
The ordinance of baptism is “for the remission of sins” (D&C 49:13). But little children have no sins. In fact, they are “not capable of committing sin” (Moroni 8:8), nor does the devil have power to tempt them “until they begin to become accountable” before the Lord (D&C 29:47). The Lord has set the age of accountability at eight years of age (see JST, Genesis 17:11; see also D&C 68:27). Those churches that baptize infants to remove original sin, or the “curse of Adam,” do so without scriptural authorization (see Moroni 8:8).