Well, I don’t believe in the philosophy of sin, however, if there’s is any such thing here it is :
‘To make other person believe that he/she deserves less’
This is equivalent to killing the greatness within a living being!
I have seen such sins being committed by teachers, professional trainers and elders – who make students/children feel that ‘they are not worth it, they don’t deserve’ in anger!
This can leave weak imprints on their mental dashboard, which might lower their self-esteem.
If you can’t encourage, atleast don’t discourage!