Louis Bouyer examines the underlying principles and teachings of the 16th century Protestant reformers. These topics include Scripture alone as source of Christian belief, justification by faith alone, God's free gift of unmerited salvation, the sovereignty of God, and the Christian responsibility toward good works.

He also presents certain problematic areas of Protestant thought, such as the denial of the efficacy of the sacraments, a conflict between various interpretations of Scripture and the Tradition of the Church, and the rejection of Church authority. He then shows how these same principles gradually weakened the various forms of Protestantism, while, at the same time, provided impetus for later reforms and renewals.

Written in 1956, The Spirit and Forms of Protestantism by Louis Bouyer still challenges both Catholics and Protestants to better understand the issues that both separate and unite them.

Topics include the Protestant teachings of:

• The Free Gift of Unmerited Salvation
• The Sovereignty of God
• Justification by Faith Alone
• The Authority of Scripture Alone as a Source of Christian Doctrine
• The Responsibility of Christians Believers Toward Good Works