The Council of Trent was called by the Pope in 1545 to answer the question, "What are we going to do about this fellow Luther?" With a little more humility, they might have figured out that their doctrine had gone somewhat astray over the centuries. But no, they refused to admit that until much later. They decided the problems the Catholic church had were twofold: (1) their priests were not well educated and (2) the reason for all the immorality in the priesthood and among the laity was all those nude statues and paintings created during the Renaissance.
To solve the second, in 1564 they sent out squads of amused artisans armed with plaster of Paris from which they fashioned history's first fig leaves to cover up the obvious source of all their morality problems. And now sometimes, on a moonlit night when sleep evades my worried brow, I lie in bed and wonder, "How could this old earth have survived without seminaries and fig leaves? What would life be like without them?" It's worth at least a ponder.
Over the centuries, movements and denominations have split off and set up shop by the tens of thousands-mostly for fleshly reasons. But in today's mobile societies, people choose a denomination mostly for reasons of psychological fit.
There are three types of Christians: thinkers, feelers, and doers. And we have denominations custom-made for each.
Long before there were Protestants, the Catholic Church tried to make room under one umbrella for all three types, with philosophy and theology for the thinkers, missions and monkships for the doers. They had an off-and-on admiration for the feelers (punctuated with periods of banishment, imprisonment, and burning at the stake--courtesy of the thinkers).
Then along came Luther (a doctor of theology, a student of Augustine's philosophy, an Augustine monk, etc.). He often declared that those Catholic feelers (the Catholics called them "mystics") would never gain a toehold in his Lutheran world. Consequently, the Reformation was primarily a theological and intellectual movement. It was woefully lacking as a revolution of spiritual maturity and lacked in giving people a practical grasp on a deeper walk with the Lord. The early Protestants hardly even made a dent in having a deeper walk with Christ.
Since that time, Europe has fought hundreds of wars over doctrinal disputes. Millions have been killed, and precious few of the fatalities have been caused by missionaries or moonbeam chasers. The bloodshed came from the intellectual, rational, logical, doctrinal differences of the thinkers. Sometime you might find it interesting to read about, say, the Huguenots just to pick one example out of many. Read about them in dungeons, tied on racks, being roasted over fires, molten lead poured in their mouths, eyes gouged out, women in birth pangs with their legs tied together while mother and child died in unbelievable agony. In each case, a theologian stood beside them, Bible in hand, to convince the tortured Huguenot that the intelligent thing to do would be to recant. And still we pass down through the generations the non-scriptural slogan, "Don't trust your feelings." At least you shouldn't trust thinkers any more than you do feelers.