God is most Merciful and loves mercy yes.. But some crimes are just too horrendous to even imagine forgiving the criminal.
However when it comes to everyday flaws and mistakes made by family, friends and acquaintances, then I often chose to forgive them with the hope of gaining God's mercy, and that others will in turn also forgive and overlook my errors and misunderstandings. Indeed no one is without sins and faults and making peace between one another and burying the hatchets is one of the better things to do in life!