Flies in the perfume make it stink alrighty.
With the imported slaves that we could see came a plethora of evil spirits we couldn’t see but sure “as hell” felt.
HOW COULD CHRISTENDOM GET SO STUPIFIED. Well it did.
I take you to mean: how could Christendom ever accept slavery as legitimate?
The short answer is, slavery is as old as civilization and is dealt with at length in the Bible.
The Bible strongly opposes slavery for God's people, but is pragmatic about others, only insisting they must be treated humanely.
Historically, over many centuries Christians were more often slaves than slave-holders, but despite numerous sanctions against slavery in many countries (see here), slave-holding was not totally abolished in "Christendom" until the 19th century.
Does that answer your question?