You can live your life angry, bitter, mad at somebody or even guilty, not letting go of your own mistakes, but you won't receive the good things God has in store.
You should protest about the views of people you disagree with over major moral issues, and argue them down, but you should not try to silence them, however repugnant you find them. That is the bitter pill free speech requires us to swallow.
I stood up as best I could to their disgusting stupidity and brutality, but I did not, of course, manage to beat them at their own game. It was a fight to the bitter end, one in which I was not defending ideals or beliefs but simply my own self.
I suppose there are a lot of reasons to be jaded or sarcastic or bitter in life, but I hang on to the reasons why life is beautiful.
Maturity is a bitter disappointment for which no remedy exists, unless laughter could be said to remedy anything.