Mormon quotes Yahweh’s answer, which lays down the principles of baptism. The Savior came to call sinners to repentance. Their repentance and acceptance of the atonement is represented by the symbolic cleansing/rebirth/resurrection of baptism. A necessary corollary is that only those who can repent may be baptized. One cannot repent if one has not sinned, and one cannot sin without understanding sin and agency.
This first statement in this verse declares the positive principle while the last suggests the reasoning that led to the controversy. Mormon’s response contradicts the assumptions that led to the erroneous practice. Although baptizing little children is heretical, it was not illogical or pagan, given a certain interpretation of gospel principles. It had arisen by mistakenly theologizing a principle that genuinely existed in the gospel, namely, the universal need for repentance.
However, “little children” existed in a pre-sinful state, potentially but not actually “capable of committing sin.” An essential element of childhood is innocence, a “free” learning period for learning right and wrong and how to distinguish between them. Learning how to exercise agency is the very reason for mortality. Even little children have that potentiality because they are born with the Light of Christ; but until they have learned how to distinguish and choose right, they are not capable of committing sin. They are capable of error—of doing the wrong things—but not of sin, which requires the purposeful exercise of agency. “For until the law sin was in the world: but sin is not imputed when there is no law,” Paul explained (Rom. 5:13).
Mormon continues quoting Yahweh’s explanation that “the curse of Adam is taken from them in me, that it hath no power over them.” Obviously, one justification for the practice had been applying the atonement to counter the Fall. Of course, this is exactly what the atonement does, as Paul succinctly stated: “For as in Adam all die, even so in Christ shall all be made alive” (1 Cor. 15:22). The correct principle, however, had been incorrectly applied. Truly, in Adam we die; that application becomes relevant as we are born and is completely balanced by the resurrection, which applies universally to everyone who is born.
However, baptizing little children misapplies the second aspect (the need for the atonement) to the time of birth. The Fall places us in a condition where both mortality (we will die) and agency (we will sin) become operational. The atonement cancels out the first condition and allows us the opportunity to accept Christ’s conditional atonement of our sin by covenant. Because we must voluntarily sin, we must voluntarily accept redemption from sin. Baptizing little children recognizes the need for baptism, but ignores the requirement of exercising agency in choosing baptism. Little children cannot sin because they are not responsible for their actions and therefore have no need for baptism.
Yahweh’s reminder that “the law of circumcision is done away in me” implies that, in fact, the Nephites were baptizing not just “little children” but also infants. In the Mosaic law, circumcision of male children occurred at the eighth day after birth. Circumcision, which represented the entrance of male children into a covenant community, had been replaced by baptism, which also marked entrance into a covenant community. The Messiah said that circumcision had been “done away,” not that it was replaced. There was no longer any need for circumcision or for the covenant that it represented. The presence of this argument suggests that infant circumcision had been used as a ritual model for infant baptism, where baptism carried the ritual meaning of entrance into the covenant with Yahweh.