The canonization of Mother Teresa of Calcutta has again drawn attention to the process of declaring a saint. To many, her canonization seems obvious; the Church, however, takes seriously its obligation to do this right, and that means following a procedure that has been in place for nearly eight hundred years.
The process begins in the home diocese of the candidate for sainthood. It begins no sooner than five years after death, unless the pope waives some or all of this time. This is done to ensure that the candidate’s popularity is not merely a passing fancy. If the local bishop agrees with the request, he applies to the Vatican for permission to proceed. The Congregation for the Doctrine of the Faith assesses the case; if it has no objections, the candidate is known as a Servant of God.
The bishop then gathers evidence of the Servant’s holiness in life and convenes a tribunal to examine it. Approval here sends the case to the Congregation for the Causes of the Saints. The evidence is reviewed by a commission in that body, and with its support, the matter will be presented to the pope for his approval. The pope then declares the Servant Venerable.
The case then waits for its first miracle. (For martyrs, this is not necessary; proof of martyrdom is enough.) When a miracle is claimed, it is investigated in the diocese where it took place to rule out all alternative explanations. This step is rigorous; if the supplicants had also appealed to the Virgin Mary, it cannot be proven that the Venerable Servant was the one who interceded here. When a miracle is substantiated locally, it is reviewed in the Vatican. The pope then declares the Servant to be Blessed.
Beatification permits official veneration locally (the Servant’s region or religious order), and then all wait for a second miracle. Assessment of this second miracle is like the first, and if it is approved by both the local bishop and the Vatican, the pope can then canonize a new saint. Canonization does more than guarantee that this person is in heaven, interceding for the faithful; it brings the veneration of the saint to the universal Church, including feast days, Masses said in the saint’s honor, churches named for the saint, even the use of the halo in artwork.