And don't forget that their ideas (especially Luther's) were not initially designed to start a new church - they were reformers trying to correct what they saw as errors, wrongs and bad practice in the Roman Catholic Church. They weren't alone in recognising these errors. To some extent they were echoing what many people already felt, so when they stepped forward they were in a real sense 'preaching to the converted'. Have a look at Chaucer's Canterbury Tales for his comments on people associated with the Church - he makes some of the same points (in a satirical way) that the Reformers made, but 100 years earlier.