Ecclesiastes 7.5 says: "It is better for a man to hear the rebuke of the wise than to hear the song of fools."
This verse was played out, almost literally, in my life this past week. I was planning on attending a concert in the near future, when a friend (and brother in Christ) told me I needed to re-examine whether or not that was something I should be doing as a follower of Jesus. The issue comes in that this was not a Christian band, and the band has a bit of a reputation for being kind of harsh and foul-mouthed. So then, his "rebuke" for me (I consider it to be an encouragement) was that I should think seriously about whether or not this was the kind of activity that I should take part in, both as a Christian, and as an example to those around me. After a bit of thought I concluded that he was right, and I thanked him for looking out for me as a brother. So in this case, his wise rebuke literally kept me from hearing the song of fools.
Proverbs 27.6 says: "Faithful are the wounds of a friend; profuse are the kisses of an enemy."
This verse inspires an interesting and accurate picture: nobody ever likes to be rebuked or told they are wrong - it's just not a pleasant experience - it hurts one's pride. But that's kind of the point: the realization that it is indeed your pride that is wounded makes you change the way you think or act and realign yourself to a more Christ-like way of life. And so, the rebuke of a friend - while difficult - ultimately leads to a more disciplined, godly life. And for that, I am thankful.