The Canonization of Saints
The word "canon" comes from the Greek word kanon meaning a standard or measuring rod.
The custom of canonization began in the early church by popular acclamation. Hence the custom of calling all the apostles "Saint."
The Catholic Church since the 10th century
has officially applied the standard of
holiness of life to certain individuals who
lived exemplary Christian lives and through
a lengthy process of prayer and study have
declared that the individual is in heaven.