John Calvin (1509–1564) was born in Noyon in northwestern France. As a young man he studied law, but in 1533 he experienced a religious crisis, as a result of which he converted from Catholicism to Protestantism. Calvin believed that God had specifically selected him to reform the church. Accordingly, he accepted an invitation to assist in the reformation of the city of Geneva. There, beginning in 1541, Calvin worked to establish a Christian society ruled by God through civil magistrates and reformed ministers.

Calvin’s ideas are embodied in The Institutes of the Christian Religion, first published in 1536 and modified several times afterward. The cornerstone of Calvin’s theology was his belief in the absolute sovereignty and omnipotence of God and the total weakness of humanity.

Calvin did not ascribe free will to human beings because that would detract from the sovereignty of God. According to his beliefs, men and women could not actively work to achieve salvation; rather, God decided at the beginning of time who would be saved and who damned. This viewpoint constitutes the theological principle called predestination. “This terrible decree,” as even Calvin called it, did not lead to pessimism or fatalism. Instead, although Calvinists believed that one’s own actions could do nothing to change one’s fate, many came to believe that hard work, thrift, and moral conduct could serve as signs that one was among the “elect” chosen for salvation.

Calvin transformed Geneva into a community based on his religious principles. The most powerful organization in the city became the Consistory, a group of laymen and pastors charged with investigating and disciplining deviations from proper doctrine and conduct.

Religious refugees from France, England, Spain, Scotland, and Italy visited Calvin’s Geneva, which became the model of a Christian community for many. Subsequently, the Reformed Church of Calvin served as the model for the Presbyterian Church in Scotland, the Huguenot (HYOO-guh-naht) Church in France, and the Puritan Churches in England and New England.