October 31, 1517 is traditionally associated with Martin Luther's Ninety-Five Theses and has become the symbolic starting date of the Protestant Reformation.
But the Reformation was not one event, one man or one issue.
Real Problems Existed
Late medieval Western Christianity faced serious problems, including abuses connected with indulgence preaching, clerical failures, political interference and longstanding calls for reform.
A credible Catholic history should say so.
The Catholic Church itself teaches that Christians on both sides bore responsibility for later divisions and that the Church continually needs renewal in the conduct and discipline of her human members.
But Reform Became Division
The controversies expanded beyond indulgences into questions including:
- justification;
- Scripture and Tradition;
- papal authority;
- sacraments;
- priesthood;
- the Mass;
- purgatory;
- saints;
- Church authority.
Different Reformers also disagreed with one another.
That produced not one Protestant church but multiple developing Protestant traditions.
Ask the Question From the Other Direction
Instead of starting with Luther and asking whether Catholicism survived his critique, start in AD 100 and walk forward.
By 1517, which beliefs and structures had already existed for centuries?
What Did Christianity Look Like Before the Reformation? →
The Crucial Distinction
The need for reform does not by itself establish the truth of every doctrinal change proposed in the Reformation.
Those questions have to be investigated separately.