I found it interesting that when Amulek admits that he was mistaken, and that he did really know something of the mysteries of God, he points to the deliverance of the people:
“for I have seen much of his mysteries and his marvelous power; yea, even in the preservation of the lives of this people.”
Perhaps not “deliverance” per se, but if it is what he means then it would follow Alma’s message in general very nicely:
“have you sufficiently retained in remembrance the captivity of your fathers?” (Alma 5)
How old is Amulek? Was he a part of the groups that left the Lamanite bondage? He doesn’t use the verb deliver, but preserve.
But it is significant I think that when he admits that he knew something of the mysteries of God, it wasn’t that he admits he had been taught already, or that he had had this or that spiritual experience, etc. He points to something everyone could say the had had: he had seen the hand of God in the preservation of the people. It was a miracle, but may or may not be recognized as so. He had mistaken: this could mean he mistakes here in his sentence, or it could mean he mistook the preservation as not a work of God, but now he sees that it was.
He was called many times. What does that mean? This sounds like something more than not realizing the hand of God was what preserved them.
When the angel appears to Amulek, he does not call him to repentance. Interesting! he went on rebelling, but the angel did not call him on it (that we hear about). He calls him to do something, not to stop doing something. Amulek obeys and it changes everything.
Also, before I head off to get kids breakfast, I noticed today another angel comes to confirm the words that Alma teaches him. He knows he is a prophet, but also receives confirmation of his words.