"Felon" is a classic "man vs. society" conflict, and like many stories of this type, the hero who challenges the corrupt system isn't just fighting the system; they're also trying not to let the experience change who they are.
Here, our protagonist Wade doesn't start off as a violent person, but several circumstances force him to become more and more violent — the burglary, his incarceration, and then his attempt to fight the system. Another movie might suggest that someone like Wade could still go back to "normal" after all this brutality, but "Felon" has a different message. Helpfully, all this is spelled out in the form of a posthumous letter John wrote to Wade.
In the letter, rather than deny the reality of Wade's experiences, John advises Wade to embrace them. But this doesn't mean that Wade has to accept becoming a brutal killing machine incapable of love. In John's view, violence is a twisted, if necessary, expression of love. Wade had to resort to violence to protect his friends and family, but to John, this is just a reflection of how much love Wade has. That may or may not be true, but it's certainly a way for Wade to move forward with his life. And in the movie's final shot, that's what he does, reuniting with his wife and son.
But "Felon" isn't just Wade's story. In the final message before the credits, the movie points out that 23 million people were incarcerated in America as of 2008. Wade's experience is the same as that of millions of people. While the movie's message is hopeful, it also acknowledges that many don't survive prison, or if they do, they may not be as lucky as Wade.
