The complete lack of self-reflection in this argument is astounding. Morality is not an immutable truth, it is a question of what is socially good or bad.
When Nietzsche said 'god is dead' he was stating now that traditional religion is gone, we must invent our own new morality. Historically people got their moral codes from religion. Western civilization is based on Christian morality.
The Modern invention of morality can either come in the form of moral relativism, or even worse moral absolutism. This article argues for moral absolutism.
To argue that everyone in history of Western civilization, and everyone who is a Christian is asshole because you believe in moral absolutism just proves you are the asshole. You are somehow morally superior to Thomas Jefferson? Really?
Worse still, is moral absolutism has caused much of the Totalitarianism of the twentieth century. If you are absolutely certain you are right, you are willing to commit any crime, take away any freedom, to do what is 'good'.