TLDR:I blame the education system for teaching people a flawed moral code

I've been thinking about this a bit lately. How do you convince someone with good intentions that they are wrong? Like people who don't think helping someone can be bad.

There is a fictional story about someone who met with Hitler in his office. He noticed a painting of a British soldier from WWI. He asked Hitler why he had that painting. Hitler told him when he was fighting in WWI his entire company was killed except him. He only survived because this man spared his life.

Incase I lost you I was trying to say that the British soldier thought being merciful and kind was a good thing and can never be bad. Its like trying to help trans people be accepted. How can it be so bad to help someone clearly suffering from something? How can it be so bad to want to help ease someone's suffering? They figure how can kindness and love be so bad?