This entire hemisphere was conquered by armies of white Christian men. They came with their horses, guns, and smallpox, and wiped out 90% of the people who had lived here for 3000 years. They justified their plundering, raping, and killing by saying that the people they found here were heathens who did not accept the true god.
Obviously, there are many people who still accept that idea — or at least they market that rationalization.