It didnt start it. That has long been brewing. Lollards, waldensians, hussites, fracitellis, all came prior.

Matrin Luthers trials, were just the cherry ontop, the last drop. Supported by the duke of Saxony in the absolute disgusting mess of authority that was the HRE and the vast spread of his translation of the bible due to the printing press was what differed him from Wickliff, why he failed and Luther "succeeded". These are the things that made the reformation spread like a fire. Luther never wanted to split the church, he was still very pro church and nobility authority over the peasents (unlike Thomas Münzer). But the Rulers wanted more power and the people were done with the clerical order and read how they arent following what jesus was preaching.

The Borgias, Pope Alexander VI was on another level of corrupt and would have probably whiped his ass with the papal robes.

Sorry its early my ADHD meds are kicking in as im typing this and history is my autistic hyperfocus :)