Why is it impossible for humans to learn a lesson in one scenario and not be able to apply it in another?

You accept a gay man yet hate the Christian man.

You accept the rich white man yet hate the poor black man.

You accept the refugee yet hate the billionaire.

None of these groups you judge in sweeping broad brush strokes are inherently good or evil. Yet you are convinced you have it all figured out. YOU know the truth of an entire group of people that YOU have boxed up into neat little segments based on some arbitrary commonality.