Theology of John Calvin  The theology of John Calvin has been influential in both the development of the system of belief now known as Calvinism and in Protestant thought more generally. "The Encyclopedia of Christianity" suggests that:  His theological importance is tied to the attempted systematization of the Christian doctrine. In the doctrine of predestination; in his simple, eschatologically grounded distinction between an immanent and a transcendent eternal work of salvation, resting on Christology and the sacraments; and in his emphasis upon the work of the Holy Spirit in producing the obedience of faith in the regenerate (the "tertius usus legis", or so-called third use of the law), he elaborated the orthodoxy that would have a lasting impact on Reformed theology. Calvin developed his theology in his biblical commentaries as well as his sermons and treatises, but the most concise expression of his views is found in his magnum opus, the "Institutes of the Christian Religion". He intended that the book be used as a summary of his views on Christian theology and that it be read in conjunction with his commentaries. The various editions of that work span nearly his entire career as a reformer, and the successive revisions of the book show that his theology changed very little from his youth to his death. The first edition from 1536 consisted of only six chapters. The second edition, published in 1539, was three times as long because he added chapters on subjects that appear in Melanchthon's "Loci Communes". In 1543, he again added new material and expanded a chapter on the Apostles' Creed. The final edition of the "Institutes" appeared in 1559. By then, the work consisted of four books of eighty chapters, and each book was named after statements from the creed: Book 1 on God the Creator, Book 2 on the Redeemer in Christ, Book 3 on receiving the Grace of Christ through the Holy Spirit, and Book 4 on the Society of Christ or the Church. The first statement in the "Institutes" acknowledges its central theme. It states that the sum of human wisdom consists of two parts: the knowledge of God and of ourselves. Calvin argues that the knowledge of God is not inherent in humanity nor can it be discovered by observing this world. The only way to obtain it is to study scripture. Calvin writes, "For anyone to arrive at God the Creator he needs Scripture as his Guide and Teacher." He does not try to prove the authority of scripture but rather describes it as "autopiston" or self-authenticating.