In this call for the righteous to physically separate themselves from the wicked, it is unclear why the righteous should “come… out” instead of expelling the wicked. In any case, Alma is clarifying that the unrepentant will no longer have place in the church, no matter their claims. Possibly Alma is simply making the same point two ways, since the wicked will have their “names… blotted out, that the names of the wicked shall not be numbered among the names of the righteous.”
This “blotting out” appears to be an actual event. Alma 1:24 recorded that, four years earlier, “the hearts of many were hardened, and their names were blotted out, that they were remembered no more among the people of God. And also many withdrew themselves from among them.” The concept that the names were part of both heavenly and earthly records is likely based on Psalm 69:25–28:
Let their habitation be desolate; and let none dwell in their tents.
For they persecute him whom thou hast smitten; and they talk to the grief of those whom thou hast wounded.
Add iniquity unto their iniquity: and let them not come into thy righteousness.
Let them be blotted out of the book of the living, and not be written with the righteous.
Reference:“Come ye out from the wicked, and be ye separate, and touch not their unclean things; and behold, their names shall be blotted out” borrows the basic form of a parallel passage in 2 Corinthians 6:17: “Wherefore come out from among them, and be ye separate, saith the Lord, and touch not the unclean thing; and I will receive you.” Clearly, the New Testament phrasing influenced Joseph’s rendering of this sentence. However, Paul is himself referencing Isaiah 52:11: “Depart ye, depart ye, go ye out from thence, touch no unclean thing; go ye out of the midst of her; be ye clean, that bear the vessels of the Lord.” Quite possibly, Alma had quoted Isaiah while Joseph translated the text into the version from 2 Corinthians.