It is a common notion that if a Christian does not vociferously call out and condemn those they perceive as sinners that they then condone their sin. It's a story of judge or be judged as far as the church is concerned.
Of course, none of this "finger pointing" squares at all with Jesus, the one who said judge not and who confirmed the equality of all sin and sinners. The claim that one man who is a sinner can gain or maintain God's favor by condemning another sinner is totally self serving and illogical.
No, I condone sin by participating in it. Every last one of us who sins condones sin, in some fashion. Unless you are perfectly sinless, you condone sin. In addition, since Jesus commanded against judgment and self righteousness, the doctrine that the church member must condemn another sinner is itself condemned by Jesus. Let he who is without sin cast the first stone.