What has Christianity truly contributed to humanity

[Bucky Ball]

Historian Tom Holland argues that the concept of human dignity and existential equality come out of the Christian tradition.

It did not. 
https://plato.stanford.edu/entries/digni...gaHistDign

Genesis 1:27
So God created man in his own image, in the image of God he created him; male and female he created them.

Proverbs 22:2
The rich and the poor meet together; the Lord is the Maker of them all.

Genesis 1:26
Then God said, “Let us make man in our image, after our likeness. And let them have dominion over the fish of the sea and over the birds of the heavens and over the livestock and over all the earth and over every creeping thing that creeps on the earth.”

Leviticus 19:33-34
“When a stranger sojourns with you in your land, you shall not do him wrong. You shall treat the stranger who sojourns with you as the native among you, and you shall love him as yourself, for you were strangers in the land of Egypt: I am the Lord your God.

It didn't come from Judaism either, but it certainly didn't come from Christianity.
"“Dignity” derives from the Latin dignitas. And while most Romans used dignitas only in its merit sense, a few, and Cicero in particular, had a proleptic understanding of dignitas that anticipated today’s moral-political sense."

"n Ancient times, the concept of dignity usually referred to respect for individuals with a high social status: a Greek king or a Roman senator, for example. It was the Stoics who first developed the idea of a dignity attributable to the human being per se, i.e. independently of individual characteristics"

https://academic.oup.com/book/5774/chapt...m=fulltext

"Originally, the Latin, English, and French words for “dignity” did not have anything to do with a person's inherent value. It aligned much closer with someone's “merit.” If someone was “dignified,” it meant they had a high status. They belonged to royalty or the church, or, at the very least, they had money."

https://solidarity.net.au/marxist-theory...00%20years.