>>779376
this from a website called newadvent.org
Perfidiæ is the complete and voluntary abandonment of the Christian religion, whether the apostate embraces another religion such as Paganism, Judaism, Mohammedanism, etc., or merely makes profession of Naturalism, Rationalism, etc. The heretic differs from the apostate in that he only denies one or more of the doctrines of revealed religion, whereas the apostate denies the religion itself, a sin which has always been looked upon as one of the most grievous. The "Shepherd" of Hermas, a work written in Rome in the middle of the second century, states positively that there is no forgiveness for those who have wilfully denied the Lord. [Similit. ix. 26, 5; Funk, Opera Patrum apostolicorum (Tübingen, 1887), I, 547]. Apostasy belonged, therefore, to the class of sins for which the Church imposed perpetual penance and excommunication without hope of pardon, leaving the forgiveness of the sin to God alone.