The Lord has described for Alma the blessings of those who do associate themselves with the church. That has not answered Alma's original question, however. What Alma needs to know is what to do with the dissenters.
While not yet answering the question, the Lord is preparing the answer to the question. The Lord indicates that contrasting to the situation of those who are called by his name (and who are numbered with the church) those who "never knew me" will arise at "the end" and will be rejected. They are rejected precisely because this Lord who is speaking is the one who redeems them, and they have not accepted that redemption (i.e. have not been baptized),