Through the centuries, marginalized Christian renewal movements have challenged the status quo of the religious establishment, often at great cost. These nonmainstream religious movements generally receive little attention in standard introductions, but Let Truth Prevail tells their story, surveying the history, beliefs, and practices of various medieval and post-Reformation European renewal movements:

17th-century German Pietists
18th-century Scottish restoration movements
Hussites
Hutterites
Magisterial Protestants and Catholics
Mennonites
The Moravian Brethren
The Schwarzenau Brethren
Swiss Brethren
Taborites
The Unity of the Brethren
Waldensians

Allen Diles classifies these groups as restoration movements, calling attention to their enduring legacies. Each reacted against perceived corruptions in the church and sought to renew faithfulness to God's truth and his intended ideals as they applied Scripture to their historical context.

Though Let Truth Prevail demonstrates the strengths of these renewal movements, the book also considers their limitations. Current readers can challenge their own self-understanding of history, God, faith, Scripture, and the practice of the Christian way by reflecting on these marginalized believers.