Kind of surprised to see the secular media, in this case the Columbus Dispatch, review Thomas J. Craughwell's Saints Behaving Badly. Reviews in the Dispatch of books about religion, at least books about religion that do not involve politics, are about as rare as buffalos in New York City.
Review is here:
St. Callixtus (an embezzler) was forgiven his sins and, in his turn as pope, forgave those of others.
He was challenged by Hippolytus, who "taught that any Christian who committed even a single mortal sin ought to be driven out of the Church and never permitted to return."
Craughwell estimates the number of saints at 40,000. If Hippolytus had his way, that number would be dramatically pared — and this entertaining book would not exist.