Written in the 1950s, this book defines and anticipates, in a prophetic way, the role of the laity in the Church, and the intimate relationship between the Church and the world. These two themes were recognized by the Second Vatican Council especially in the two constitutions "On the Church" and "The Church in the Modern World."

Von Balthasar's "bastions" are barriers erected over the centuries which separated the laity from the clergy and the Church from the world. He pleads for a Church that interprets "the signs of the age," grasps them and answers them, allowing herself to be awakened by the Holy Spirit and by the age "from the bed of historical sleep for the dead of today." The new function of the Church is to be the "yeast of the world"--she must understand herself as the "instrument of the mediation of salvation to the world." Stressing that the hour of the laity is sounding in the Church, von Balthasar makes it clear that the "true program of the Church for today is: the most powerful radiance into the world through the most immediate imitation of Christ."