Final answer:
John Calvin wrote the Institutes of the Christian Religion to articulate and explain the principles of the Protestant Reformation and the beliefs of Calvinism, distinguishing it from Catholic teachings.
Step-by-step explanation:
John Calvin wrote the Institutes of the Christian Religion to explain the Reformation and Protestant beliefs. This seminal work was intended to lay out the tenets of Calvinism, which was part of a wider movement challenging the prevailing Catholic dogma and practice. Building upon the foundation laid by Martin Luther, Calvin sought to further articulate the views and theological principles of the growing Protestant movement. He emphasized the sovereignty of God, the authority of the Scriptures, and salvation through faith alone. Unlike Luther, Calvin was also known for his role in establishing a theocratic government in Geneva and for his ideas about predestination.