I think of this verse in Sirach… “Admonish your brother, he may not have done it, but admonish so he will not do it again.” Although I think we must take the Wisdom books with a grain of salt, for sometimes “admonishing” people especially if you are not sure they have done anything, will make them angry and less likely to change. I think it is better to ask people questions in a roundabout way without directly accusing them of any vice… like Jesus asked the Pharisees, “Who does the will of my Father–he who says ‘I won’t do what you want’ but then goes and does it, or he who says ‘I’ll do what you want’ and doesn’t do it?” The Pharisees answer “the first does the Father’s will.” So they condemn themselves… Jesus doesn’t have to do it for them… you can ask people, what is the purpose of getting drunk? for example. And, What is the purpose of drinking alcohol? Do you think some things are like buying soft socks–they are very pleasant at first but with use they become boring and unpleasant and sad? you can ask, Is this really the life you want to live? Are you happy?–but these two questions are best saved for people who know you care about them. You can make people think, plant seeds… but being nice does not mean burying your head in the sand if YOU KNOW someone is hurting herself… if you are not sure, be on the alert, ask certain questions so that if they are engaging in self-destructive behavior, those questions will make them think… without you knowing if they are doing anything or not.