And it came to pass that the people did still remain in wickedness, notwithstanding the much preaching and prophesying which was sent among them; and thus passed away the tenth year also; and the eleventh year also passed away in iniquity. And it came to pass in the thirteenth year there began to be wars and contentions throughout all the land; for the Gadianton robbers had become so numerous, and did slay so many of the people, and did lay waste so many cities, and did spread so much death and carnage throughout the land, that it became expedient that all the people, both the Nephites and the Lamanites, should take up arms against them.