Forgiveness costs us nothing. All our costly obedience is the fruit, not the root, of being forgiven. That's why we call it grace. But it cost Jesus his life. That is why we call it just. pg. 37
Where did forgiveness and justice meet? At the cross.
(Quote taken from Fifty Reasons Why Jesus Came to Die by John Piper ©2006 by Desiring God Foundation and published by Crossway).