As I’ve researched how a virtuous person was named a saint in Christianity’s early centuries, I’m having “Oh so that’s why” moments.
As in oh so that’s why Boniface was considered a saint soon after his martyrdom in 754. Oh that explains the speculation that Frankish Queen Hildegard’s reason to summon Saint Lioba to court was an attempt to control the frail old nun’s relics. Hildegard could be reasonably certain her friend would be canonized soon after her passing.
What brought this on was my confusion over Saint Christopher’s status among the divine. He was revered in medieval times – who better to protect you on the road than a tough guy – but his status was reduced to a local cult in 1969, with the reform of the Roman Calendar. (Reports that the Church ruled he didn’t exist are greatly exaggerated.)
Martyred probably in the third century, Christopher was canonized long before today’s formal, meticulous process, complete with investigation and documentation.
The earliest form of canonization was a way honor martyrs and treat their sacrifices as cause for celebration. The 1907 Catholic Encyclopedia cites second century martyr Saint Polycarp and how the faithful gathered his bones and planned to mark the anniversary of his death.
Later, the decision of sainthood went to a local bishop, who would send word to neighboring churches. In the fourth century, veneration also applied to confessors, people who lived in heroic virtue but died in peace. (For a modern example, think Mother Theresa of Calcutta.)
In the eighth century, it is easy to imagine a bishop saying a short time after the funerals for Boniface and Lioba that they were saints.
The pope always had the authority to decide whom the universal Church should honor as a saint. But by the 11th century, the standards for sainthood among bishops had gotten too lax, and popes decided that councils would examine the facts. Controversy over who qualified as a saint continued until 1634, when Pope Urban VIII published a bull that made canonization and beatification exclusive to the Holy See.
Fast forward to 1969 and the reform of the Roman Calendar. The concern: so many saints’ feast days on the calendar detracted from the more important Lent, Advent, and Sundays. The calendar was rearranged, feast days were categorized, and the saints it included were more diverse in geography and throughout the centuries.
Even with a reduced status, Christopher is still a saint, and you can celebrate his feast on July 25. Can you still pray to him for safe travel?
Here is how Father John Echert concludes an eloquent answer on EWTN about Christopher and his status, “I, however, continue to honor and seek the intercession of such saints, including Saint Christopher, trusting that no sincere prayer offered by one in grace goes unanswered. And I continue to give out Saint Christopher medals to others, for their protection.”
“St. Christopher was demoted but remains a saint,” by Ellen Creager of Knight Ridder Newspapers, Abilene Reporter-News, June 6, 1998
“St. Christopher” by Francis Mershman, The Catholic Encyclopedia. Vol. 3. 1908.
“Beatification and Canonization” by Camillo Beccari, The Catholic Encyclopedia. Vol. 2. 1907. 
EWTN, Fr. John Echert answering a question about Saint Christopher
The Oxford Dictionary of Saints, Fifth Edition Revised, by David Farmer
“The Life of Christopher,” The Golden Legend, from the Medieval Sourcebook