What is an example of a historical event that shows that strength of our beliefs is tested when we encounter conflict?

The Spanish Inquisition is one historical example that comes to mind, as is the current situation in which various radical Muslims have made people choose between conversion and death, both, actually, two sides of the same coin.  In each instance, the strength of people's religious beliefs have been tested by the most extreme conflict.  

In the Spanish Inquisition, those who were of the Islamic and Jewish faiths were rounded up and forced to convert...

The Spanish Inquisition is one historical example that comes to mind, as is the current situation in which various radical Muslims have made people choose between conversion and death, both, actually, two sides of the same coin.  In each instance, the strength of people's religious beliefs have been tested by the most extreme conflict.  

In the Spanish Inquisition, those who were of the Islamic and Jewish faiths were rounded up and forced to convert to Christianity (specifically Catholicism, the only form of Christianity there was at the time), or they were to be put to death or expelled.  Those who agreed to convert were known as Conversos.  Some of those who did not agree were expelled, but many were killed.  At least some who converted did maintain their religious practices secretly and carried them with them to the new world.  (The Inquisition, which occurred over 500 years ago, has recently made the news, since Spain has decided to offer Spanish citizenship and apologies to the descendants of the Jews who were expelled.) This was a severe test of faith for Jews and Muslims, and many people died for their respective faiths.  

In the Middle East today, people not of the Islamic faith are being subjected to the same treatment. Some are fined, some flee, some are enslaved, and some are killed because of their faiths.  Christians, Jews, and Yazidis have been relentlessly persecuted and slaughtered, in the case of the Yazidis, to the degree that this is considered by the world to be genocide.  The strength of the beliefs of these people has been subjected to the most extreme conflict, and there are many who have died for their beliefs.

It seems that in over 500 years, we have learned little or nothing about allowing people the freedom to believe as they choose.  In spite of knowing history, we seem to be condemned to repeat it.