Do you get back what you give to people?

If you make someone happy will you get happiness in return.If you put a smile on a poor kid's face will it make you get your wish .If you hurt someone do you get hurt yourself.Be nice to people why it's so important to take care of other's feelings.Why hurting someone is considered such a big sin.Why do we cry for our sins.Why do we have to pay back for our deeds.He was a playboy he played with girl's feelings he never cared for anyone till a girl came into his life .She made him fall deep for him but in the end she left him.Maybe this happened to make him realize that every girl feeling's matters.You do good and you will get good back .Allah instantly pays you back for your good deeds but sins He keeps giving you chance to repent & when you have passed your limit he punishes you.She treated her step daughter so cruelly and in the end she died with nobody to look after her.Her real children abandoned her .You can't get inner satisfaction when you have cut someone into pieces.For the time being you maybe happy but One day Life will make you realize what you did wrong to others & because of you how much did anyone suffer.At that time you may have no contact with that person But you can ask for Allah's forgiveness .Maybe you can meet that person later in your life and you can ask for forgiveness.Once a glass is broken the pieces can't be fixed but heart's have the tendency to heal but the damaged part will always keep bleeding .Be careful You get Back what you Give to People.Hope to hear from my readers as i keep writing and i get no comments so i'm still confused what do they feel about my writing!!!!