Immediately after the Gospels, the New Testament takes up the history of the early Christian Church, describing the works of the 12 disciples and introducing Paul, the man whose influence on the history of Christianity is beyond calculation. Teacher, preacher, conciliator, diplomat, theologian, rule giver, consoler and martyr, his life and writings became foundations for Christianity. He inspired a vast, serious and intelligent literature that seeks to recapture his meaning, his thinking and his purpose. In his letters to early Christian communities, Paul gave much practical advice about organization and orthodoxy. These treated the early Christian communities as something more than a group of people who believed in the same faith: they were people bound together by a common spirit unknown before. The significance of that common spirit occupied the greatest of Christian theologians from Athanasius and Augustine through Luther and Calvin. In this work, Schweitzer goes against Luther and the Protestant tradition to look at what Paul actually writes in the Epistles to the Romans and Galatians: an emphasis upon the personal experience of the believer with the divine.
Paul's mysticism was not like the mysticism elsewhere described as a soul being at one with God. In the mysticism he felt and encouraged, there is no loss of self but an enriching of it; no erasure of time or place but a comprehension of how time and place fit within the eternal. Schweitzer writes that Paul's mysticism is especially profound, liberating and precise. He introduces readers to his own point of view at once, then describes how he came to it, its scholarly antecedents, what its implications are, what objections have been raised, and why all of this matters.