It is neither unbiblical nor mean to confront people about sin.
“Rebuke a wise man and he will love you.” (Proverbs 9:8)
“Brothers, if someone is caught in a sin, you who are spiritual should restore him gently.” (Galatians 6:1)
“Do not regard him as an enemy, but warn him as a brother.” (2 Thessalonians 3:15)
“My brothers, if one of you should wander from the truth and someone should bring him back, remember this: Whoever turns a sinner from the error of his way will save him from death and cover over a multitude of sins.” (James 5:19-20)
Too many of our friends wander from God because we don’t love them enough to come along side of them and help them.