God doesn't want strife to be existing between us but peace, love, and tranquility. As God forgives us of our trespasses He expects that we too should forgive others of their own trespasses and shortcomings. He set a good example for us to live by.
It may be difficult at times but this should be the manner by which we model our life. Not forgiving does not do us any good. It could be a reason why our prayers may be hindered sometimes because God said that if we come before Him while we are keeping malice with others we should first of all go and settle or differences before returning back to Him.
If we do not forgive people we are not emulating Jesus Christ the way we ought to. In a way we are indifferent from people of the world because to most of them there's nothing wrong with unforgiveness. But according to the christian context there's everything wrong with it.
