What do you do if you hate a person?

even though you hate that person,you can't take revenge on him/her.whenever you see him/her,just smile.you don't need to be his/her friend but never show hatred in your face because deep down inside that person's heart,it is still good.i hope u believe me and will benefit from it.think about it.if you are that person,would you like people to take revenge on you?