Be good, if you can

Around the year 1500, the Italian priest Don Filippo Neri helps street kids and orphans in his poor little chapel. He is no clergyman by the book, but a true believer in terms good and bad and he teaches this to his children. Neri is not very well-seen by the church and his only "friend" is the dry, humorless Ignatius De Loyola. But Neris real counterpart is the devil himself, working in endless incarnations in Neris direct neighborhood, trying to seduce his kids. His newest kid is the young thief Cirifischio, making a lot of problems. When Cirifischio has an argument with a young boy of a local aristocrat, the boy turns out to be a girl, the young Leonetta, some kind of a sex slave for her owner. Neri adopts her too, and the young people fall in love. 15 Years later, the devil is back and leads Cirifiscio onto a murder. Now lawless, the thief must flee Neri and leave Leonetta back...