why did St. gregory the great become a saint?

Question

When did he become a saint?

Answer 1

I guess the pope felt like canonizing him.

Answer 2

If you are a believer then you are a saint.
In Christianity, a holy person, living or dead; a person who has been saved . Saint is the French word for “holy.” Many churches reserve the title of saint for persons who have died faithful to their Christ. The Roman Catholic Church and the Eastern Orthodox Church require certain procedures before people can be officially named saints; this procedure is called canonization. On to the question. Gregory Born c. 325 into a wealthy Christian family in Cappodocia (what is now central Turkey) just after the final Roman persecutions of Christians, Gregory become a Christian only in his early twenties, and reluctantly agreed to become Bishop of Nyssa at the urging of his brother Basil. The two of them, along with their friends the poet-theologian Gregory of Nazianzus and John Chrystostom, Patriarch of Constantinople, are considered four great Cappodocian fathers of the church.

Answer 3

Saints have no basis in Bible scripture. they are purely a Catholic invention.