The dichotomy between Christ as the Good Shepherd and the opposite choice, the Devil, is further clarified. The difference is by definition: “whatsoever is good cometh from God, and whatsoever is evil cometh from the devil.” As verse 41 points out, that dichotomy holds for humankind’s actions. If we do good, it comes from Christ. If we do not good, it comes from the Devil. Our choices are manifest through the nature of our actions.
It is important to remember that Alma is speaking of the final judgment. There is no discussion of repentance precisely because it is a discussion of the final times, times after which the judgment of our actions comes, times after opportunities for repentance have passed.
What we become will depend upon the master we have chosen, Christ or the Devil. The reward reflects the choice of master; life everlasting, or death “as to things pertaining unto righteousness, being dead unto all good works.”