I think it's interesting to look back over the history of humankind in terms of hatred and intolerance, especially over things such as race and religion. There seems to be a recurring pattern in human beings where we oppress others who are different from us. What I find most interesting is how many of the groups who are victims of the oppression eventually end up becoming the oppressors, and very often for the same reasons.
For example, the historian Tacitus reported that Romans were intensely cruel to early Christians. Many were crucified, fed to wild animals, and killed in other horrible ways for the simple fact that they were Christians. Yet Christians killed people in similarly horrible ways, believing they were witches.
The Hebrews believe they were enslaved by Egypt for centuries, yet many Jews were involved in trading slaves (source).
I bet if one were to look at any race or religion in history, one could find a time when that race or religion was hated and oppressed by some other group. What's more, I bet one could find a time when that same group became the oppressor to another group different than they.
Similarly, the early LDS suffered great hardships as a consequence of following their beliefs. They were forced to leave county after county, were robbed, tarred and feathered, and even killed for no reason other than being LDS. Those who stuck to their convictions regardless of the consequences are admired and revered in LDS culture. And yet, if a person sticks to his convictions, and they are somehow in conflict with the LDS faith, he is quickly attacked, hated, shunned, and often oppressed.
Why is it that people are so bad at remembering when they were on the receiving end? They gasp in horror at the stories of Joseph Smith, Jr. being chastized for reporting visions, and the early LDS being driven out of their homes. Yet these same people harshly attacked and some ostracized me when I announced that I was following my conscience. We all want to be allowed to follow conscience: to walk to the beat of the drummer we hear.
LDS know the horrors of being oppressed for belonging to something they felt they could not deny, yet the LDS sure were intolerant of anyone with Black skin, even when they shared the exact same religious beliefs! Once again, the oppressed became the oppressors.
Even more recently, the Church retains a disdain for homosexuality (here is one example, here is a response). I was told by a stake president a few months ago that he was "born a believer." I don't think he could stop believing in the LDS church if he tried. Yet he expects a person who is born with same-sex attraction to give up what is at his or her core. He would be furious if I told him he had a flaw that needed to be fixed. Yet he expects that individuals who feel they were born homosexual must deny it, or be fixed.
Why does this double standard persist throughout history? Our own predecessors knew exactly how wrong and horrible it was to oppress others for reasons such as skin color and religious beliefs - because they were on the receiving end! Why then do we, who have finally been accepted for who we are and what we believe, still not accept others for who they are and what they believe?