Short answers, pulled from the story.
Reformed Christianity, also called Calvinism, is a major branch of Protestantism that began during the 16th-century Reformation in Switzerland. It differs from Lutheranism chiefly in its view of the Lord's Supper, holding that Christ is spiritually rather than bodily present in the Eucharist, and it places strong emphasis on God's sovereignty, covenant theology, and the authority of scripture.
Reformed Christianity began with Huldrych Zwingli in Zurich, Switzerland, during the Reformation. John Calvin became its most influential theologian, writing the Institutes of the Christian Religion between 1536 and 1539, though the term "Calvinism" was first applied by opposing Lutherans in the 1550s and Calvin himself disapproved of the name.
The Five Points of Calvinism are summarized by the acrostic TULIP: total depravity, unconditional election, limited atonement, irresistible grace, and perseverance of the saints. The acrostic was used by Cleland Boyd McAfee as early as around 1905, with an early printed appearance in Loraine Boettner's 1932 book, The Reformed Doctrine of Predestination.
According to a 2020 survey, Presbyterian and Reformed Christians numbered approximately 65,446,000, Congregationalists approximately 4,986,000, together totaling around 70,432,000 people, or 0.9% of the global population. The World Communion of Reformed Churches reports more than 100 million members in 211 denominations.
Calvin advocated a mixed government of democracy and aristocracy, favored separating political power among institutions through checks and balances, and insisted the church retain independent authority from the state. Calvinist Congregationalists who founded Plymouth Colony in 1620 and Massachusetts Bay Colony in 1628 practiced self-rule and separation of powers, contributing to the political framework that shaped the United States Constitution.
The Arminian Controversy arose in the 17th century when Jacobus Arminius and his followers, called the Remonstrants, were forcibly expelled from the Dutch Reformed Church over their view that God's choice of whom to save is conditional on his foreknowledge of who would believe. The dispute produced the Canons of Dort, which affirmed unconditional election and became the basis for the doctrines of grace in mainstream Reformed orthodoxy.