“Once a Catholic Always a Catholic”? Not Necessarily.
Many Catholics casually say the following line to ex-Catholics in order to get them back into a Church building: "Once a Catholic, always a Catholic." It sounds welcoming, but it's theologically wrong. This is because the Magisterium of the Catholic Church and the Church Fathers, St. Thomas Aquinas and the Popes all taught: A bad Catholic never ceases to be a Catholic, provided his failure be not faith-based but morality-based (and also provided those moral failures be not excommunicable.) On the other hand, a baptized person who has purposely rejected even one tenet of the traditional Catholic faith is a heretic who is no longer Catholic. Furthermore, a baptized person [...]