However, we should bear in mind that true forgiveness is conditional upon repentance ( a change of mind and heart). God doesn't forgive us unless we repent!
Take heed to yourselves; if your brother sins, rebuke him, and if he repents, forgive him; and if he sins against you seven times in the day, and turns to you seven times, and says, ‘I repent,’ you must forgive him. Luke 17:3,4 RSV
Of course, if you think forgiving a person refers to letting go of your ill feelings toward him, you can do that whether he repents or not. Indeed, you should do that whether he repents or not. But that's not what forgiveness is. True forgiveness is a restoration of a relationship with another person, based on that person's repentance.