Grace is the Love of God calling us to wholeness in Christ through confession and repentance of sin. Confession of sin and repentance are our responses to the Love of God. Sorrow is a significant part of repentance. Peace comes through God's provision of forgiveness and restoration!
One cannot rightly speak of Grace without an acknowledgment of sin. Sin requires grace and grace demands it place that can be accommodated only through repentance.
2 Corinthians 7:9-10
9 Now I rejoice, not that you were made sorry, but that your sorrow led to repentance. For you were made sorry in a godly manner, that you might suffer loss from us in nothing. 10 For godly sorrow produces repentance leading to salvation, not to be regretted; but the sorrow of the world produces death.
1 John 1:9
9 If we confess our sins, He is faithful and just to forgive us our sins and to cleanse us from all unrighteousness.
1 John 2:1
My little children, these things I write to you, so that you may not sin. And if anyone sins, we have an Advocate with the Father, Jesus Christ the righteous.