Canonization was once referred to as “being raised to the altars,” and that phrase shows how hard the Church’s job is to investigate so that the person’s life would be an example. It’s an investigation of sins, but also of teachings and opinions that, while not keeping the person out of heaven, have problems that make the person an unlikely or problematic role model. One of our Holy Father’s first acts in this area was to return a beatification candidate to investigation out of concern that he had written some anti-Semitic things. If so, the person might well be forgiven by God and in heaven, but not necessarily worthy of canonization and “raised to the altars” as a role model for the faithful. Some holy people have written so much that even though we are confident of their holiness, there is concern that a patch of bad teaching or outlandish political opinion would make them less worthy as role models, and so it takes decades to go through the pertinent material.