“The Church” never departed from truth.
However, some members of the church did. No one denies that individuals, sometimes many individuals, went against the church teachings into things like selling indulgences (for their own personal gain), went against their vows of poverty, chastity and obedience as priests; were lazy, greedy, sinful etc.
Since clergy were held to a high standard, and a small (though still too large) number were extremely blatant in their sinning, and since any ‘chastisement’ from their superiors tended to be ‘too little, too late’, a number of well intentioned people stepped forward in an effort to purify, not so much “the church” but some of the church’s ‘clergy’.
And then, as often happens, they went a little too far. They became more concerned not with what was offending God (as they had been at first), but what offended them. And in order to bolster their own selves and to ‘prove’ that they were being more ‘godly’ than the clergy, they started to ‘cherry pick’ scripture.
Instead of arguing (quite correctly) that a man who had vowed chastity should not be fornicating, they started to go even further. Why, when one looked at “scripture” and not “the Church” (“The Church”, after all, was full of SINNERS but ‘the Bible’ was not --here is the start of Biblolatry), were priests ‘celibate’ to begin with?
And ‘who’ started this clergy ‘power’ anyway?
Anticlericalism became more and more vocal and vicious. People looked at the very high profile ‘sinner’ they either knew or had ‘heard of’, and ignored the hundreds of quiet and godly clergy in their midst. Hey, these people ‘shut themselves away’, these people ‘mumbled’ in a ‘foreign language’. Sure, they may ‘act nice’ right NOW. . .but can you trust them? Can you trust them not to be like the Borgia pope? They aren’t ‘like us’. They are trying to ‘keep’ us from having the Scripture because they’re afraid we’ll find out ‘we’ are as good as ‘they’ are. IN fact, we’re BETTER because ‘we’ are ‘pure’ and ‘we’ follow the BIBLE and not some ‘man’.
Welcome to the ‘reformation’ as most know it–not the beginning with its honest concern over individual wrongs, but the fight to the literal death over doctrine and the wholesale abandonment and ‘rewriting’ of Scripture to bolster the fighting.