Even non-Christians affirm that Christianity is the bedrock of western civilization.
[In] the West, the countries that were once collectively known as Christendom continue to bear the stamp of the two-millennia-old revolution that Christianity represents. It is the principal reason why, by and large, most of us who live in post-Christian societies still take for granted that it is nobler to suffer than to inflict suffering. It is why we generally assume that every human life is of equal value. In my morals and ethics, I have learned to accept that I am not Greek or Roman at all, but thoroughly and proudly Christian.
Historian Tom Holland: Why I was wrong about Christianity
Today the cornerstone of international law is the sacred, what is sacred in humanity. You should not kill. You should be responsible for a crime against the sacredness of man as your neighbor…. Made by God or God made man,…in that sense, the concept of crime against humanity is a Christian concept and I think there would be no such thing in the law today without the Christian heritage, the Abrahamic heritage, the biblical heritage.
Atheist philosopher Jacques Derrida
When one gives up Christian belief one thereby deprives oneself of the right to Christian morality. Christianity is a system, a consistently thought out and complete view of things. If one breaks out of it a fundamental idea, the belief in God, one thereby breaks the whole thing to pieces: one has nothing of any consequence left in one’s hands. Christian morality is a command: its origin is transcendental, it possesses truth only if God is truth-it stands or falls with belief in God.
Atheist philosopher Friedrich Nietzsche
For the normative self-understanding of modernity, Christianity has functioned as more than just a precursor or catalyst. Universalistic egalitarianism, from which sprang the ideals of freedom and a collective life in solidarity, the autonomous conduct of life and emancipation, the individual morality of conscience, human rights and democracy, is the direct legacy of the Judaic ethic of justice and the Christian ethic of love. This legacy, substantially unchanged, has been the object of a continual critical reappropriation and reinterpretation. Up to this very day there is no alternative to it. And in light of the current challenges of a post-national constellation, we must draw sustenance now, as in the past, from this substance. Everything else is idle postmodern talk.
Atheist philosopher Jürgen Habermas