If you brainwash people with religion, you can get them to believe that genocide is OK:
In 1966, the Israeli psychologist Georges Tamarin presented, to 1,066 schoolchildren ages 8-14, the Biblical story of Joshua’s battle in Jericho:
“Then they utterly destroyed all in the city, both men and women, young and old, oxen, sheep, and asses, with the edge of the sword… And they burned the city with fire, and all within it; only the silver and gold, and the vessels of bronze and of iron, they put into the treasury of the house of the LORD.”
After being presented with the Joshua story, the children were asked:
“Do you think Joshua and the Israelites acted rightly or not?”
66% of the children approved, 8% partially disapproved, and 26% totally disapproved of Joshua’s actions.
A control group of 168 children was presented with an isomorphic story about “General Lin” and a “Chinese Kingdom 3,000 years ago”. 7% of this group approved, 18% partially disapproved, and 75% completely disapproved of General Lin.
Which is why religion is evil and it should be illegal to proseletyze religion to anyone under 16.