On November 11, 2023, my friend, colleague, and hero Ayaan Hirsi Ali released a statement explaining "Why I am Now a Christian”. What follows is my response, “Why I am Not a Christian,” and why in any case the alternative to theistic morality is not atheism but Enlightenment humanism—a cosmopolitan worldview that places supreme value on human and civil rights, individual autonomy and bodily integrity, free thought and free speech, the rule of law, and science and reason as the best tools for determining the truth about anything.