Why should we forgive others?

Why should we forgive others even if sometimes we don't think they are deserved to be forgiven? Just because we are told by Bible to do so?
为什么我们得原谅不值得原谅的人？仅仅是因为圣经如此教么？

Matthew 6
14 For if you forgive other people when they sin against you, your heavenly Father will also forgive you. 15 But if you do not forgive others their sins, your Father will not forgive your sins.

From my point of view as a human being, it is a must to forgive others for our own goodness. Life and memory is like a bottle, if it fulfilled full of bad things, there wouldn't have any room for good things. If we don't forget bad experience , good experience would't come. We want the hate, anger, sadness bite your heart at the night when we are alone?
在我从人的角度看来，原谅是为自己好。 生活和记忆就像个瓶子，坏事不走，好事如何载入？我们期待夜深独自一人时被恨、愤怒、悲伤蚕食我们的心么？

No.

Forgiveness to others is an exit for the negative feelings. The key to forgive is to understand. First, Understand that we are not the only person gets hurt. How many people have hurt others means how many people have been hurt. Who hasn't been betrayed ever? Who hasn't been taken money from ever? Other people can heal themselves, we also can. Second, understand the people who hurt us are sinner as we do no matter whose sin is more evil. They have their own excuse to hurt others as human being's sin. How much we can blame them, how much they can find the excuse to protect themselves and blame us back. So, stop figuring out why they have done that to us, how could they, what should they pay for it. As long as what inside us aren't taken away, we still are ourselves and be able to build up our own life again
原谅他人是给负面情绪一个出口，关键是要明白，你不是唯一被伤害的，谁没被背叛戴绿帽子过？谁没被人抢走钱过？我们有多少可以指责他们的，他们就有多少借口保护自己再指责回来，因为我们和他们一样都是罪人，无论罪多最少。停止纠结为何被伤害，他们欠了我们多少，只要我们内在的东西还在，生活可以重新再来（挫折是“破坏而不是毁坏“）。

Just admit they are sinners. Their sin is none of our business. That is something between them and God.
承认她们是罪人，他们的罪和我们无关，是他们和上帝之间的事。

In 佛教, it is said 执念 is not a good thing. If we are sticky to the person or the debit they owed us, probably we are going to meet them again in 再世轮回。Do we want all the 狗血 scenario happen again?
佛教里执念也是不好的，如果执着于旧账或许来生还会重逢，我们想让狗血剧情重演么？

No. At least I want we are clear as I don't want see them again.

So, just forget about it. Time can cure us. Let it go. Even don't remember them at all. That's it.