Courage and sensitivity.

Dear Self,

Any chance you could help me work out when I need to have the courage to tell someone they are out of line and when I need to have the sensitivity not to point it out?

I seem to struggle knowing the difference. 

I really don’t want to be unkind, but I also don’t want to stand by when someone is being hurtful and could really do with a little bit of perspective.

Any suggestions are welcome.