And to top it off, each group hated and still hates other groups of religious believers.<quoted text>
...gotta love science as it goes back billions of years pieceing together where we came from with actual physical evidence
....religion only goes back a few thousand years when man created many different forms of their Gods. Created out of fear. Through a process of elimination over the centuries the number of gods has been whittled down to just a few.
When they were allowed to kill each other as heretics without spending time in prison for such lunacy ... the Christians claimed it was because they were motivated by love to please GOD.
If that isn't insanity ... the word insanity has no meaning in earth-time.