A person could read every text from and about a single religion, talk to people in the religion, even be part of that religion and STILL not understand it fully. Why? This is because religion and individuals are constant evolving.
In the history of the world, there have always been lives lost, people harmed and discriminated against basis on religion. What many of us fail to see this that, regardless of a religion’s text, rules, laws, governing, etc.., there will always be some of its followers who either stay steady in the whatever they consider its original intent to be or others who see the need to either push change, or to at least, make changes within themselves. Over the last 50 years or so, we’ve seen some religions evolve, maybe because they realize the only way to survive is to become kinder and more accepting? Even the church I was raised in as a child didn’t allow people of color to hold certain positions until 1978. Crazy, Right? Even now, you can have two churches in the same town, preaching the same religion, but one has evolved to be kinder and more accepting. Change in religion comes slowly but it comes.
Individuals are much the same. They may follow a religion, it may be an intricate part of their life, but they may actively or passively remove themselves from the negative elements of their belief system. They may stay with a religion despite not accepting some of the elements of it. They may live in a state of cognitive dissonance, constantly reconciling, and trying to make their religion and personal beliefs fit together. (Some/Many people spend their whole lives this way.)
We cannot understand what a person believes based solely on their religion because people are too complex. We do not know what goes on in the mind of the individual, we do not know if someone is hoping for things in their faith to change. We cannot know for certain if they will be kind and honest despite their belief system calling for something else towards some people, and we do not know what kind of cognitive dissonance a person is dealing with. Assuming that we understand any other human we do not know intimately is one of the worst mistakes we can make. (Especially since many of us do not fully understand ourselves.)
I as an individual I can condemn hate, violence, bigotry, and oppression. I also cannot personally judge an individual based on their belief system, without knowing what they personally believe. With some religions, it may be near impossible to know what someone really believes due to the nature of their belief system and where or if they diverge from their religious teaching. In these cases, I advise caution over hatred and judgment. (Hate only begets more hate.) If you decide to be cautious, don’t forget to be kind and lead by example!
I am not a perfect individual, but I will continue to decide my feelings about other human being basis on how they treat me and how they treat others. I will not be judge and jury over another human being because their religion, I only will hope the best for them. I will hope they are or will become a kind, loving person, regardless of anything else.