Few matters produce more public interest and public anxiety than sex and religion. Much of the political contention and division in societies across the world centres on sexual topics, and one-third of the global population is Christian in background or outlook. The issue goes to the heart of present-day religion. The Bible observes that God made humanity ‘for a little while lower than the angels’. If humans are that close to angels, where lies the difference? Is it human sexuality and what we do with it? In a single lifetime, Christianity or historically Christian societies have witnessed one of the most extraordinary about-turns in attitudes to sex and gender in human history. There have followed revolutions in the place of women in society, a new place for same-sex love amid the spectrum of human emotions, and a public exploration of gender and trans identity.