Rhetorical: Nephi understands that even in this particular apostasy, the Nephites retain a belief in these revered ancestors and in God. Their understanding of God has apparently changed in that they are beginning to reject to the Atoning Messiah, but nevertheless the fundamental belief remains. With this base, Nephi argues the obvious, that God was with these revered prophets of accepted tradition.
What Nephi now does in his discourse is to shift that accepted position into a criticism of their refusal to accept the coming Messiah. We must remember at this point that the Nephite tradition understood Jehovah and Jesus to be the same, and therefore when Nephi suggests that “he is God, and he is with them,” he is referring to Jehovah. This is an important connection for his argument, and he uses that linkage to turn the belief in tradition to a required belief in the Atoning Messiah. Nephi notes that God gave glory to these revered prophets (an accepted fact, and Nephi has also indicated that they have predicted the coming Messiah), and that he gave them glory “because of that which is to come.” That which is to come is the Atoning Messiah. Nephi tells the people that God revered these prophets precisely because they predicted the Atoning Messiah who would come.