What did John Calvin preach or stress in his writing?

John Calvin emphasized the sovereignty of God, the importance of scripture, and the doctrine of predestination in his writings. He advocated for a reformed theology that underscored salvation by grace through faith, rejecting the notion of works as a means to earn salvation. Calvin also stressed the necessity of a disciplined Christian life and the establishment of a church governed by biblical principles. His key work, "Institutes of the Christian Religion," systematically laid out these theological concepts and their implications for both individual believers and the church.