Jesus Christ is the instrument of man’s reconciliation with God. Moroni is not teaching the nature of the atonement, but rather using the atonement as a witness to the power of God. As he does so, he reiterates doctrines from the Nephite prophets. Nephi himself taught this doctrine in 1 Nephi 15:31 and 2 Nephi 9:11. Alma taught of raising man from temporal death in Alma 11:42; Alma 12:23-24; and Alma 42:8-9. Contrasting this statement of Moroni with the others noted, we can see that a significant difference in the usage is precisely this distinction between statement and explanation. For Moroni, this is an accepted teaching being used as evidence. In the other instances, it is something to be explained and taught.