Where does Christ's teachings tell people to do those things?

Why are you asking me? Certainly, nothing about Christ's teachings stopped them.

I'm asking you because you're the one who just laid the blame of the last 2000 years of bad things on Christ's teachings, and not on mankind's natural behavior. Somehow it was what Christ taught, because it didn't stop people from doing bad things.

I didn't lay the blame for anything on Christ's teachings, I laid the blame on Christianity.

If you can't look back at history and see the difference between theory and practice then I don't know what to tell you.

Christianity is Christ's teachings, and any other definition is a strawman. What you're talking about is man's sinful nature, and that is separate.

So... you literally look at events like the Crusades, anti-semitism, slavery, the treatement of native Americans or any number of horrors done by Christians in the name of Christ and with the authority and sanction of the Christian church .... and admit absolutely no relationship between any of that and Christianity? No, Christianity isn't just the teachings of Christ, any more than any religion, or American law is just the Constitution. Christianity is also what Christians do, it's politics and government and militarism, culture and pop culture. Dogma and folklore.

What I'd like to be talking about is the relationship between the Christian religion and Western imperialism and the consequences of Christian conquest on the narratives of history (specifically the narratives of groups oppressed by that religion.) What you're engaging in is pedantry and a gross application of what I'll call the True Christian fallacy. Fair enough. We can't have a conversation about this. Good night.

When you use circular definitions, as you're doing now, you can re-define a word to be whatever is convenient to you. If Christianity is also defined by what Christians do, then what defines a Christian? You have to ground it in a concrete definition at some point, and that definition is: the teachings of Christ. If a Christian acts in a way that is against the teachings of Christ, then that is not Christian behavior, and is not representative of Christianity. That's a pretty simple and unambiguous concept.

Your "No True Scotsman" variant just shows that you don't really grasp this idea. Ironically, what you're doing by making Christianity a grab-bag of bad behavior from people you don't like, instead of grounding it in a clear and unambiguous definition, is a clever perversion of this fallacy.