The Word, Church and Sacraments in Protestantism and Catholicism is a theological classic. It seeks to foster unity and deeper understanding among Christians by comparing the Catholic and Protestant views of Scripture, Church authority, and the Sacraments. Bouyer, one of the greatest theologians of the 20th century and a convert from Protestantism, contributed significantly to the movement out of which came the Second Vatican Council's efforts to promote Christian unity.

In The Word, Church and Sacraments, he shows how Catholic teaching is often misunderstood by Catholics and Protestants alike, and how this teaching is fundamentally compatible with key positive elements of Reformation thought. He also examines the main points of disagreement between Catholicism and Protestantism, and demonstrates how Catholicism, properly understood, maintains the theological balance necessary to uphold some of the main truths on which Catholics and Protestants agree.