A heart that is pure is the kind of heart that God wants from us; a heart free of strive and grudges. If we call ourselves christians and we still bear grudges in our hearts then we are not getting it right because this should not be how a believer should act.
1 John 3:15
Whosoever hateth his brother is a murderer: and ye know that no murderer hath eternal life abiding in him.
The word "brother" stated in the above passage is not just referring to our biological sibling. It equally goes out to our brethren in faith and everyone generally in life. Instead allowing hate or grudges dwell in our hearts we should allow love to take over instead. Love should lead us and not hate. When we have love in our hearts we can forgive people no matter the offense or hurt they may have brought our way.
God does not want us live our lives keeping malice with people. It is far different from what He wants from us. Forgiveness is not for the benefit of the people we are forgiving. It is actually for our own benefit. It liberates us from every heaviness that the heart should go through and makes us aligned with God.