I have an odd question: Can a Protestant convert to become a “secret Catholic”? In other words, no one knows about the conversion except the priest. I know that according to canon law in Europe, one cannot retain membership in a Protestant church and hold membership in the Catholic Church at the same time. But can one secretly convert without public ceremonies?
Although a person cannot be both a non-Catholic and a Catholic at the same time, for just cause a conversion to the Church may be kept private. Public ceremonies are not required for reception into the Church. Just cause for a private conversion would include cases where someone’s life would be endangered by the announcement of conversion or where announcement of a conversion would cause public scandal. Ordinarily though, a “secret conversion” is really just a prudential postponement of an announcement of having become Catholic. A true unwillingness to be known as a Catholic probably would indicate that someone is not yet ready to become Catholic.