Sounds like good advice and very much like the Golden Rule to do unto others as you would have them do unto you. Just as surely anyone can have a moment of goodness, the best of us can have moments of badness. I did here today, in fact, in another thread! So I think you're wise to seek to bring out the best in others. God willing, they'll live up to it!

On a related note, this also puts me in mind of the psychological phenomenon of the self-fulfilling prophesy! Expect the worst and you'll probably get it!