My Two Cents:
As an independent-thinking, open-minded individual, having seen, heard, and experienced many things in my 7+ decades of life, and I have to say that a person's beliefs are basically nurtured by years of conditioning, training, etc.
This comes from others, mentors, groups, with a determined, and often strict emotional attachment to certain beliefs.
Once the beliefs are implanted, deep-rooted, they become part of that person's life forever.
And that person will do anything to protect, justify, and stand up for said beliefs.
Mind you, I believe in the fundamental freedom to live your life the way that you want. - and I am for equality, as long as it doesn't interfere with others freedoms.
However, it also has it's consequences, when it comes to others with different strong beliefs.
This then amounts to hatred, arguments, violence, biases, and sometimes wars.
I suppose it's a part of Human Nature, a part that sadly all have dealt with at one time or another.
These beliefs need not be so disruptive or dangerous, but the fact is that they've been taught for centuries, and thus have become so strongly rooted in many, are virtually impossible to eliminate or control.
The old saying of "Keep your business to yourself" is a strong clue that this "belief system" has successfully created its roots and divisions among civiliation.
As I've mentioned on occasion, I base my life and views on facts, reality, not hearsay or some book-taught ways that I am supposed to follow.
I'm a person who enjoys my freedom to be myself.
Because like the internet itself, social media, etc., there are biased opinions due to different beliefs.
I've seen what it's amounted to in others that I've personally dealt with.