What has Christianity truly contributed to humanity

[Thumpalumpacus]

You can say, "well, we just changed our minds," but that doesn't really explain to me why or when our values changed. Or whether our current thinking is somehow more "natural," or likely to endure.

You must, however, from this adduce that morals change over time, as you tacitly admit here.

Or you might simply say that you support Biblical slavery and be honest about it.

You cannot, however, argue that the Bible is inerrant and argue that slavery is wrong -- unless you admit that morality is relative and/or subjective, or put shortly, not absolute.

This is the Christian conundrum, and on more issues than slavery. Morality is both relative and subjective, but you cannot acknowledge that without undermining your own god's alleged moral authority.