Ps. 141:5 Let a righteous man strike me—it is a kindness;
let him rebuke me—it is oil for my head;
let my head not refuse it.
Is it better to be in the presence of wicked people who flatter, or righteous people who reprove?
The Psalmist picks the latter and this is health to his bones rather than a false praise today and who knows what will come tomorrow. I don't think it is our norm to want to be struck by a friend, but in the end it is much better than being left alone. You know who your true friends are when they tell you have stuff in your teeth:) If we are not approachable enough to our friends to have them tell us, we will walk around and everyone will want to say something, but won't.
This is all the more true with things that really matter. If our friends are telling us something in our lives that need addressing, then we should listen and be thankful they are friends enough to tell us. It is not easy to hear, but if it brings us to repentance and helps in our sanctification, then it is good.
We need to both accept the reproof and we also need to be willing to speak the truth in love. Gal. 6 talks about the brother caught in a transgression, but what about when we see a "Non sin" issue in another's life? In a spirit of meekness, knowing that we all have things we need to work on, we should go to them and point out what we might be seeing. I am not suggesting to be judgmental, but what is the best way to maximize our influence?
We must be a teachable, humble people as we walk through this short life on earth. Many will say hurtful things, but those who really care will say healthful things and we should invite it.