Personally, I forgive many times out of obedience to one of many commands to do so in the Bible. Ephesians 4:32 says, “Be kind to one another, tenderhearted, forgiving one another, as God in Christ forgave you.” Then Matthew 6:12 says, “forgive us our debts, as we also have forgiven our debtors.” Again Colossians 3:13 commands, “bearing with one another and, if one has a complaint against another, forgiving each other; as the Lord has forgiven you, so you also must forgive.”
Forgiveness is a requirement of living in Christ; it can be done as a volitional act of the will; basically, you just decide you will forgive someone. Matthew 18:21-22 adds “Then Peter came up and said to him, ‘Lord, how often will my brother sin against me, and I forgive him? As many as seven times?’ Jesus said to him, ‘I do not say to you seven times, but seventy-seven times.’” Thus forgiveness is a continuing act towards a person.
But let us consider grace, where Romans 5:8 says, “but God shows his love for us in that while we were still sinners, Christ died for us.” And also, Romans 3:24 says “and are justified by his grace as a gift, through the redemption that is in Christ Jesus.” God goes far beyond just forgiving us. He first provides a way to forgive by sending His Son to die and then pursues us to avail ourselves of the forgiveness. We can learn from this: forgiving through obedience to His commands to do so is good but it is even better to eagerly and joyfully pursue to forgive people. What if we grew to have hearts that searches out every avenue to forgive those who have wronged us?
In a posture of eager forgiveness, there is no need to wait years or decades to forgive. Time does not heal all wounds. We use the example of Jesus and Stephen, as they were being killed, cried out “Father, forgive them” and “Lord, do not hold this sin against them” (Luke 23:34, Acts 7:60). When a heart is eager to forgive; it is offered immediately; it is the first response to an attack. This posture of forgiveness keeps our heart from building up bitterness and resentment.
*disclaimer on forgiveness. Forgiveness is not the same as reconciliation; the other person does not need to know you are forgiving them, this is an internal heart issue between you and the Lord. And forgiving someone does not mean that you trust them; it just means you do not judge them or hold them to account for how they have wronged you or others (the justice system may still need to bring them to account for laws broken, but you do not personally).
