"Institutes of the Christian Religion (Vol. 1 of 2)" by Jean Calvin is a work of systematic theology first published in Latin in 1536. Written initially as an introductory textbook on Protestant doctrine, it defends Reformation believers against persecution and false accusations of heresy. Calvin covers fundamental Christian teachings including the Ten Commandments, sacraments, and justification by faith, while vigorously challenging Roman Catholic doctrine. Expanding through multiple editions until 1559, it became the foundational text for Reformed churches and remains one of Protestantism's most influential theological works. (This is an automatically generated summary.)