"Hatred does not cease by hatred, but only by love; this is the eternal rule" - Siddhartha Gautama "The Dhammapada: The Sayings of the Buddha"
Forgiveness is both a process and a result. However, forgiveness as a result is binary in nature; either you have forgiven or you have not. Our relationship with forgiveness and our misconceptions of it comes from our societal programming. We are raised to tell people we perpetrate against that we are sorry. What does that actually mean? We aren't told to ask for forgiveness, we are not taught how to repent nor are we taught how to forgive others, whether they seek our forgiveness or not. It is not very surprising though as most of our moral standards come from our religious backgrounds. Religions take on forgiveness is contradictory at best. The bible tells us on one hand "an eye for an eye" and on the other "to turn our other cheek". The Quran is no better; here we are told that we shan't harm the creations of God, but on the other hand wage war against those that offend him. Our prison system also focuses on punishment not on reform, which is because society does not understand what it means to forgive. We are brought up to be vengeful. No wonder we are confused as to what forgiveness is and how to do it.
I would therefore venture to state that our confusion relating to forgiveness is based in ancestral and cultural karma that we keep perpetuating. This confusion causes us to, unnecessarily, hold on to bitterness, anger, hurt, guilt, shame, etc. We have a need to show others how they've hurt us by holding on to it, thus only perpetuating our own hurt. It is hard for us to let go. Often times we have left a part of ourselves in the experience that we find hard to forgive. We essentially use our conscious mind as an anchor to hold on to these hurts in the illusion that by committing them to our memories we will be protected from similar situations in the future. This is, however, a contradiction because whatever you hold on to will resonate from you and thus will attract those experiences again.
"The weak can never forgive. Forgiveness is the attribute of the strong." - Mahatma Gandhi
Forgiveness does take strength, strength to, with your awareness, overcome and supersede your conscious and subconscious minds. The good news, being strong or weak is a matter of choice, one may just not have awoken to it yet.
Leading up to forgiveness, we develop and embody compassion and acceptance towards ourselves, our experiences and those that are participants in our experiences. Along that path we also work on our boundaries. However, once you have love and compassion for yourself and others and accept your experiences and the path of others, boundaries tend come quite naturally as you have a greater understanding of yourself and your journey. Forgiveness as a process often requires a great deal of patience. Some experiences click in no time and you immediately see the gifts from it and can forgive, other experiences you need to revisit and view from every conceivable perspective to gain the understanding to achieve forgiveness. These perspectives do include your own choices and involvement in the experience. It is critically important that you remember to forgive yourself, even if you were the one who was the victim in the experience. You are the constant through every experience in your life and your choices lead up to and through every experience, so you must include yourself in the forgiveness process, for whatever choices and actions you took or, for that matter, didn't take.
You may at this point have gathered that forgiveness is not an external process needing the involvement of anybody else but you. Forgiveness is an internal process. However, you may choose to involve others in the process, as in expressing your forgiveness or inviting someone to forgiving you, but if you do not bring that external experience inside and embody it, you will not progress.
Two key elements to consider in your healing process are:
As previously described you will have used some sort of argument for holding on to the hurt and refraining from forgiving; e.g. I show how hurt I am, My hurt protects me, etc. You may also realise some secondary gains, such as people feeling sorry for you and showing you pity, others might not confront you because they know how hurt you are, etc. It is very important to remember that forgiveness is a choice and as individuals we have to come to our own intrinsic realisation that the benefits of letting go and seeing the positive intents and secondary gains of holding on to the hurt as illusionary. Everyone will come to their own realisation in their own time, even if it is after no longer being on this physical plane.
You will have to be clear that you might feel this interesting sense of mourning when you do achieve forgiveness, because you have let something go that has been part of you for so long, you might even have identified with it. You will possibly mourn the secondary gains that were dear to you. If you are prepared for these feelings you can set yourself up to understand and release the mourning without much trouble.
Forgiveness does not mean that you agree with what you did or what someone did to you. It simply means that you accept that it did happen and that you are ready to not let it rule you and by letting go of the emotional attachment and, thus, retrieving the fragment of yourself, you learn from the experience and move on. It allows you to understand you boundaries and continue to use them dynamically to gain flow in your life. You become less stoic in your approach to your boundaries and the challenges you accept in life. As with all experiences, you have the choices of either, staying, leaving or changing, that is expressing and setting your boundaries. The learning experience is always about yourself and how you respond to challenges, it is not about others as in, "I know he's an a-hole and I will stay away from him!", that is an opinion with negative connotations that will hold you locked in the space of "hurt" preventing you from forgiving. Simply accept all elements of the experience as being there to help teach you something about yourself.
I use a two pronged approach; evoke a memory of the experience and observe my emotions and ask my higher self. If you can recall the experience and you have no negative feelings that bubble up or reveal themselves to you, you have very likely forgiven. If all you can see is the gift from the experience, you have absolutely forgiven. You may also ask your higher self, "Have I fully forgiven all parties and elements involved in this experience?". The answer might not be immediately forthcoming, but, again, exercise patience and be observant as to when the answer comes. It might be in a song, a sign, or something else, pay attention, but obsessively so.
Once you forgive you simply cannot hold on to the hurt.