In the history of the Catholic Church there are many accounts of messages received from the souls of the departed. The truth of these accounts is subject to the ordinary laws of historical criticism, and some accounts have certainly been proved doubtful. Others leave no room for prudent doubt. As a rule, God permits a soul only occasionally to communicate momentarily a warning, or a request for prayers, but nothing fantastical. Likewise, the messages are spontaneous, and not due to the curious efforts of people seeking the truth from the dead. The Church tests the messages received, or claimed as received, in order to discern whether good or evil spirits are responsible for the communication. (1) The message must in no way conflict with Catholic teaching or moral principles. Gal. I., 9. (2) The person who claims to have received such a communication must be characterized by sound common sense, and even be undesirous of such occurrences. (3) The effects of the message must be good, the recipient being moved to a holier life, and to nothing indecent, shameful, or contrary to Christian standards.
Radio Replies Volume 1 by Rev. Dr. Leslie Rumble MSC and Rev. Charles Mortimer Carty