From "Love Wins" by Rob Bell,
Have you ever been in an argument and you knew exactly what not to say?
You knew exactly what would most wound the person, what would unnecessarily
drag the past up, what would get right to the person's heart in the quickest
, most hurtful way - and yet you said that very thing anyway?
...
Once you are awaken, you will put yourself at alert and refuse to say such
things, to him, to her, to anyone. Thereby you will be able to keep a loving mind, always smile and never speak with malice again.
Inner peace 其实并不难, just a matter of practicing your mind.