When you say:
"all people have to do what they are supposed to do"
so that means that the thief has to steal and the drug dealer must sell drug and the killer must kill and the teacher must teach and the doctor must diagnose, etc.
My question now which sentence is better
"all people have to do what they are supposed to do" or "people must do right things which benifits humanity and avoid things which can harm humanity"?
Also your statement nomerci is very wide and not specific,
I have another question to you nomerci:
do you a prefer a person who tells how to reach the target easily and correctly or a person who keeps you lost and wasting your time?