On holding grudges

How does the concept of God as judge influence grudge-holding in the Christian?

“You have the rest of forgiving others. Until you understand that God is really the Judge, that no one will get away with anything, that everybody will be held accountable. That every person in this room, either Jesus paid for your sins or you will pay for your own sins forever. When you realise that, it’s very difficult to hold a grudge–ever again. You begin to realise that you’re not wise enough to hold a grudge, you’re not good enough.You don’t have the right to hold a grudge, you don’t have the right to be the judge! You don’t need to be the judge! God’s wise enough, He knows what people deserve, He knows what they’ve gone through, you don’t. God’s good. No one will get away with anything.

“As soon as you understand the judgment of God, you can relax. If there’s anybody in this room who’s bitter and angry and cannot forget what somebody else has done to them, don’t you see how restless you are? Because you don’t really believe God’s a judge. You’re trying to be a judge yourself, because we all believe in justice. If we don’t think there’s a God who’s doing it, then we’re going to have to be the judge. Friends, don’t you see, without judgment there’s no rest. No rest for you–knowing you’re forgiven. No rest for you–being able to forgive.”

—Tim Keller, Why doesn’t life make sense: His justice