Now Alma begins to introduce the most important part of his sermon. This is where he solves the dilemma. He has created a condition where choice can lead to eternal condemnation. Clearly this is not the preferred outcome of earth life, and there must be a way out of temporal and spiritual death. There is such a way, and it is through the Son. The Son provides the Atonement, and this allows men to repent. Through repentance, the effects of sin may be removed, while the benefits of agency are retained. Men may learn to chose God, and not harden their hearts. Then their sins may be removed, and they may stand justified before the bar of God. Mercy may override justice because the sins are removed.
From a theological standpoint, we must understand that justice will always prevail. Justice requires that a sinful man be excluded from the presence of God. Mercy does not contradict this requirement. What mercy does is remove the sin, and therefore justice does not apply.