Sin is inevitable, which is why it requires forgiveness instead of condemnation.
‘Forgiveness' is exactly what we need, as opposed to 'forgiven'.
I don't know what you mean by this.
But what do you mean by the word? You must know the cliche that will pop into almost everyone’s head when you use it without the reasoning behind it.
It sounds cliche because it's a mantra. When you study the mantra deeply and critically enough, you will understand it.
I'll try to explain once more, however, by saying that sin is like crime that we get punished for without exception. It's not like crime where there's a statute of limitations or you can otherwise escape justice.
Sin causes harm, so what we sow we reap. You think, maybe, that if you kill someone before they kill you that you can escape them killing you back, but somehow what goes around comes around and people can't escape the effects of their own actions.
That's just part of why we need ultimate forgiveness, but it also has to do with the vicious cycle of falling deeper into sin as a result of feeling inescapably damned to sin/hell. It also has to do with the fact that sometimes when we seek forgiveness from people we have sinned against, they are not loving/selfless enough to forgive unconditionally, so they will try to enslave you as a condition of forgiving you, and that's why Martin Luther risked his life to point out that salvation is by faith alone and not by works/deeds that you do in order to 'buy indulgence.'
To be forgiven only benefits the one doing the forgiving.
Forgiveness involves both parties understanding what, how and why the trespass took place.
One is relatively easy. The other takes a lifetime at best.
Forgiveness is a spiritual state within yourself that you have to believe in to be saved from sin. If you can't believe that God can forgive everything in order to put us on the right track, there is the story of Christ paying for everyone's sins so that you can stop worrying about what you have to do to be forgiven and instead can get the real business of how to live to honor the fact you've already been forgiven and saved.