The fact must be faced that Christianity did not challenge the institution of slavery until, basically, the 1800s. It even took ten years from the Establishment of Christianity in Constantinople to the abolition of the gladiator “games.” And it took the martyrdom of a monk to accomplish that transformation.Having said that, the critique of historical Christianity must include the question, “Compared to what?” And that challenge is devastating to the anti-christian presumption of moral authority - for the simple reason that it was only Christianity which had ever considered slavery to be wrong.
The delegitimization of slavery occurred under the leadership of Christians generally, of Protestant Christians especially, and of British Protestant Christians in particular. No other cultural tradition did anything much more than grudgingly follow the Christians - at a time when the scope of the British Empire was at its zenith. See, Part II of Black Rednecks and White Liberals by Thomas Sowell
Sorry I mentioned it.
Next time I’ll shut up.