Is Matthew 28:19 not encouraging us to kill people? Maybe I have chosen a somewhat clickbaity title, but let me just explain why I think so:
In this verse, Jesus is encouraging us to spread Christianity to "all nations". Being a nation "a country, especially when thought of as a large group of people living in one area with their own government, language, traditions, etc.:", I assume that it means to the whole world.
But encouraging people from one place to go explore the whole world is a horrible thing when they don't know almost anything about diseases. When Europeans colonized America, they killed 25–50 % of the population only by spreading the diseases to people how hadn't had contact with them before. Only it Mexico, the population went from 25 to 30 millions to 3 millions because of it!
So that's why I think this verse encourages killing, because it says "spread Christianity to the whole world" without giving the necessary information to prevent millions of deaths.