Praising or criticizing some but not others for the same actions is how bigotry begins, no matter how good your intentions. If you can't apply the way you treat a group to all people, you may be a bigot and not know it. All bigots believe they're just being realistic, not biased.
People are not their actions, and they are not the belief they currently hold. You cannot change a person's beliefs but you can change their belief about their belief by showing them the consequences of their actions.
Just reacting to wrongs in the world gives no direction or stability. Imagine a world with no bias or bigotry and treat others as those people would. It's how their world became that way.
Blame belongs only to the individuals who did the act, not those you associate with them. Blaming people who did no wrong does nothing but keep people divided by empty hatred. Blaming descendants is to blame the innocent for centuries to come. If it is to end, it is to end now.
Actions are made with the intention of specific consequences and designed assuming a near accurate model of the world. When you are misled, the consequences of your actions will not be as you intended. You are literally impaired from acting freely. Lying takes away your freedom.
Everyone came to their beliefs through conclusions, whether they are through direct experience, being told by someone they believed or through their imaginations. Even if they don't remember why, there's always a cause.
It's too easy to attribute maliciousness when their reasons make no sense to you. If they make no sense, then you don't know enough about their worldview. Start at how they believe others see them and where they got that idea.
People, especially children, tend to believe assertions automatically (see e.g. Gilbert et al. 1993; Jaswal 2010). Asserting beliefs based on limited or potentially faulty evidence therefore tends to propagate error. So love of truth demands we openly express uncertainty.
Never hide your true self from anyone, including yourself. Be honest, don't act a certain way for people. It is important you know yourself, so that you can love yourself and show others who you truly are, before someone can love you.
Some people struggle in life and aren't able to improve our world, which is ok, but if that doesn't describe you, embrace the fact that you have the opportunity to improve our world. We will all die someday, but a positive impact you make on others and our world is immortal.
Although people often think that our standard of living is only to be improved upon, numerous previous civilisations with great standards have ceased to exist; likely so will ours, so let's enjoy it while it lasts...