"Faithful are the wounds of a friend, but deceitful are the kisses of an enemy."  (Prov. 27:6)

     Most wise managers in the business world do not want "yes men" (someone who agrees with everything you say regardless of what they think) working for them.  Why?  Because integrity and honesty are required in order to make healthy decisions, not flattery.
      It is no different when it comes to "friends".  A "yes friend" is not a true friend.  When you are doing something that is bad, harmful or dangerous, a true friend will give you the "medicine" you need, even if the needle stings or the medicine tastes bad.  They will make you face who you are, what you do, and the necessary remedy.  You will feel bad, but it will pass!
     Sadly, the true friends are often the ones treated like the enemy.  Yet the enemy does nothing but say "yes" and make you feel like the greatest.  An enemy will let you live recklessly, but a friend will save you.
     The Apostle Paul was one who cared deeply: 
          "..though I caused you sorrow by my letter, I do not regret it; though I did regret it - for I see that that letter caused you sorrow, though only for a little while - I now rejoice, not that you were made sorrowful, but that you were made sorrowful to the point of repentance; for you were made sorrowful according to the will of God, in order that you might not suffer loss in anything through us."  (2 Cor. 7:8-9)
     Be a friend, (Prov. 28:23) and listen to your friends.  Who are they?  Generally they will be your parents and/or Christian brothers and sisters.  But the greatest friend is Jesus!