Christianity's Dangerous Idea

Alister McGrath's comprehensive historical study examines the Protestant Reformation not as a single sixteenth-century event but as an ongoing revolution centered on what he terms Christianity's "dangerous idea" — the belief that all Christians have the right and responsibility to interpret Scripture for themselves. Writing as both a theologian and intellectual historian, McGrath traces how this principle of individual biblical interpretation emerged from Martin Luther's challenge to ecclesiastical authority and became the defining characteristic of Protestant Christianity.

McGrath argues that the Protestant emphasis on the "priesthood of all believers" and direct access to Scripture unleashed forces that transformed not only Christianity but Western civilization itself. He demonstrates how this interpretive freedom led to the explosive diversity of Protestant denominations, each claiming biblical warrant for their distinctive practices and beliefs. The work examines how Protestant principles influenced the development of democratic ideals, scientific inquiry, and individual liberty, while also acknowledging the fragmentation and theological chaos that resulted from rejecting centralized religious authority. McGrath shows how the same interpretive freedom that enabled Protestant missions and social reform also produced sectarian divisions, competing claims to biblical truth, and the challenge of maintaining doctrinal coherence across diverse communities.

The book has remained influential for its balanced assessment of Protestantism's mixed legacy and its insight into contemporary Christian divisions. McGrath neither celebrates nor condemns the Reformation's consequences but offers a nuanced evaluation of how the principle of individual interpretation continues to shape Christianity today. Who should read this: Students of church history and anyone seeking to understand why Protestant Christianity developed such remarkable diversity, along with theologians and pastors grappling with questions of biblical authority and ecclesiastical unity. This work is less suitable for readers seeking devotional material or practical guidance for Christian living.