The Catholic Church defines canonization as the official process by which one is made a saint. Early in church history, those who were considered Catholic saints would be placed in tombs that would be considered sacred. When the quality of those granted sainthood was called into question, it was decided that more care should be taken as to who was worthy of this honor.
This idea developed through the centuries, culminating in the establishment of an official process to investigate sainthood eligibility by Pope Gregory XI in 1234.
Though popes throughout church history have revised the qualifications one must meet in order to be named among the Catholic saints, the core process has remained constant. The process for establishing sainthood begins when a person dies who has fame of sanctity.
When this occurs, their life is investigated by a bishop, who evaluates whether they are deserving of being named among the Catholic saints. If this person is found worthy, their information is sent to the Congregation for the Causes of the Saints, which attempts to establish if the person lived according to the virtues of faith.
If the candidate satisfies these requirements, he or she may be considered venerable. Throughout this process, a devil’s advocate, or person who argues against canonization, is commissioned.
The final step in the process of being named among the Catholic saints is beatification. In order to become beatified, the candidate must be credited with a miracle. This will grant the candidate restricted veneration. After this is established, the recognition of a second miracle is required for the candidate to be called among the Catholic saints.
Throughout Church history, the proof of miracle has been a requirement for all that are selected for candidacy, aside from martyrs, who may be canonized without proof of a miracle.