Rhetoric: As Mormon summarizes his argument, he makes a wonderful allusion to his earlier discussion of judging. He now declares that he is judging his audience. Since he has said that one who has the Spirit of Christ may judge, he is certainly claiming spiritual confirmation of this judgment and declaration. This is also a reprise of the “judgment” he declared in verse 4.
In this case, he judges his listeners to be good (and therefore able to lay hold on the good things): “I judge that ye have faith in Christ.” Mormon provides this statement as a benediction, but one with teeth in it, for he also declares “if ye have not faith in him then ye are not fit to be numbered among the people of his church.” If we are to be members of this church, faith is a requirement.
This is not to say, of course, that we must have a full or strong faith. As Alma2 taught in the discourse recorded in Alma 32, there are stages in the growth of our faith, and all stages are welcome and essential in the church. But Mormon is saying that, if we are to have a church based on Christ, then it is absolutely essential to have faith in Christ. The two concepts cannot be separated.