Because the Lamanites remained angry, they hit the Nephites "on the cheek" and made them carry heavy burdens like "a dumb ass" (21:3), just as Abinadi had prophesied (Mosiah 12:2, 5). The Nephites murmured, complained, and tried to get out of bondage. They went to war three times, and kept losing. Things became worse, with more widows and orphans each time.
There may well be a lesson here. How does one get out of any burdensome situation, including spiritual bondage? What is the wrong way? When we have a sin, what is our first reaction? The Nephites were trying to fight their way out of sin on their own. When you do that, how successful are you likely to be? Not very. It simply does not work. This is one of the world’s ways of trying to lead us away from the right path. The world will tell you, "You’re strong; you are capable; you can do it." But don’t be fooled It didn’t work for the Nephites, and it does not work for us either.
What’s more, once the Nephites had fought and failed, what did they do next? They gave up. They thought that there was no way they could escape it. This is another wrong idea the world tells you, "You cannot help it; just don’t worry about it." Both of these, of course, are wrong ways to get out of spiritual bondage.