Get rid of all bitterness. So we are under command to get rid of it. How do we do that? We forgive - even if the offending party doesn't ask for it. That's tough to do. At Life we play songs about this topic such as Forgiveness from Matthew West and 7x70 by Chris August, Toby Mac has a song about Forgiveness as well... many artists do. It's no coincidence as if we let unforgiveness fester in our souls it rots us from the inside out and bitterness sets in and we become ineffective for Christ - the enemy of our souls wins.
So how do we beat this? Forgive. Overcome evil with good as Scripture says. Don't give the Devil a foothold. Easy to say, tougher to do...