When we cannot bare the thought of another person without being filled with anger and a desire to lash out, we are experiencing malice. Peter admonishes us to "put malice aside". If I find a crack running up the length off my drinking glass, I will throw it away (put it aside). The glass has become dangerous to my health.
Malice affects us more than it affects the one we hate. It eats away at our peace and eventually our character. The other person will find excuses for their behavior toward us and move on while we are stuck in the never ending, never satiated condition of bitterness and hatred.
But if we remember how unfairly we treated God, and how much we needed both his correction and his mercy, we are more able to leave that person in God's capable hands and moving forward.