no canonization–the word means “added to the list”–as a formal process done today of investigating the saints life, work, writings etc., documenting miracles, and the stages of Servant of God, Venerable, Blessed and finally Saint, were not introduced until about 1000 years ago, and have been refined over the years.
before that saints were acclaimed by the faithful and bishops, either locally or by the universal Church
the calendar of saints, the days their feasts are celebrated by the local churches or the universal church, which are optional memorials and which are fixed feasts of the Church, has also changed over time. and if a saint’s feast has been moved or made optional it does NOT mean he has been “demoted” or “un-canonized”.
all the apostles except John were martyrs and then as today a martyr who is killed for a reason directly related to his Christian witness is made a saint without needing miracles, although miracles have been attributed to the intercession of many if not most martyr saints. John, as is done in the formal process of today, was acclaimed saint because of outstanding virtue, holyness, and steadfastness under persecution and in suffering, and for his great work in service of the Church.
the complete process is documented and referenced in links stickies on the spirituality forum, or just jump to the CA homepage and click on the relevant library articles for a more complete history
if you are a new user welcome, and take some time to explore the site, including and especially the homepage, and the forum resources in the stickies, because you will get much more benefit from the site if you do this first.
