"Letter to a Christian Nation" is a book by Sam Harris, published in 2006. It serves as a critique of religious belief, particularly focusing on Christianity in the United States. Harris argues that faith can lead to harmful consequences, such as intolerance and violence, and he advocates for a more rational, secular approach to ethics and morality. In the book, Harris addresses the misconceptions about atheism and emphasizes the importance of reason and scientific inquiry. He encourages readers to question religious doctrines and consider the implications of faith on society, urging a shift towards a more evidence-based worldview.