Two things strike me as odd. To forgive someone is to not take something you find hurtful or difficult into account.
It is something people and God do. This is not unique to God, but is part of life, christian or not.
To not see this is simply not accepting normal relationships, and getting upset and then moving on.
The second idea is not forgiving is ok. For me two issues are important. Recognising you are hurt and a particular situation was important to you. The second is separating other peoples behaviour from you reaction. If you ever talk to a doctor or policeman, you realise they have to do this every day. They are called to behave in a particular way, no matter the provocation. This distancing approach is important. It makes it possible to stop being a victim and becoming a positive contributor.
Forgiving people is actually removing yourself from the situation and being objective. At this point you can often judge it properly and you no longer are reacting from personal revenge. Listen to Jesus before Pontious Pilate. "You do not have the power of take my life unless it has been given to you."
All things are in the hands of the Lord. It is his purposes that are being worked out. It is why Paul talked about the privilege of sharing in His sufferings.
Forgiveness is probably one of the hardest issues we have to face, because it is about submission and humbleness, letting go of our rights and exercising love to others.
On one basis, christian brothers and sisters who refuse to repent of calling me a hypocrite, an unbeliever, say I lie and intend evil against the Lord, have refused to repent and continue in like mind, should I forgive them?
The problem is they are blinded by their belief system, which says I must be those things to not agree with their ideas of OSAS. The language looses its meaning because it is so unreal and founded on good things, and the subject matter so serious. For me it makes a mockery of faith itself, and the Lord, so I just say, "Father forgive them for they know not what they do."
If is like saying you do not have to forgive because everyone is already forgiven. This is just a denial of hurt, upset and holding this against another. But some seem to dwell in this kind of world, which I cannot relate to at all.