Mormon is frustratingly obtuse in his first declaration. Alma teaches: "that which was to come." What was that? Was this the calamities that Abinadi had foretold? It was the coming of the atoning Messiah. That was the essence of Abinadi's message. It was the understanding of the atoning Messiah that had converted Alma, and the rest of the passage confirms it. Alma is preaching of Christ.