Alma continues to describe the sins of the Jaredites. One of the factors demonstrating how far they had gone away from God was that they had “murdered all the prophets of the Lord who came among them to declare unto them concerning their iniquities.” They not only would not repent, but they also killed those who preached repentance to them.
The only good lesson that Alma takes from the Jaredites is associated with their bad example. When modern readers approach the book of Ether, we note the faith of the brother of Jared. We find inspiration in that early part of the text. Alma did not focus on that part at all. There is no hint that the Jaredites were ever righteous. The message that Alma took from the book of Ether, and the message that Mormon will use as he shapes his own narrative, is that they were a people who abandoned God and whose secret combinations led to their destruction. They are the example of what such actions would mean for the Nephites, should they follow that path, which Alma makes explicit in verse 31.