"Our blessed and loving Father, give to us, we pray you, the knowledge of the awfulness of sin. Teach us how that those who live today in apparent quietness as the results of sin live to-morrow in dire destruction and wickedness. Save us from evil, and may we overcome it with good. Amen."
(Blogger's note: this not only applies to those sinners who go unpunished for a time, but to those who remain silent as to sin. There's a saying, I think, to the effect of: "Those who remain silent to sin become accomplices to it.")