The Reformation: Luther, Calvin, and the Protestant break

In 1517 a German monk and professor, Martin Luther, posted (or circulated) his Ninety-Five Theses protesting the sale of indulgences, payments said to reduce punishment for sin. What began as a call for debate became a movement when Luther pressed deeper: that a person is justified (made right with God) by faith alone (sola fide), by God's grace, apart from earning it; and that Scripture alone (sola scriptura), not church tradition or the papacy, is the final authority. Refusing to recant at the Diet of Worms (1521), Luther was excommunicated, and, protected by German princes and spread by the new printing press and his German Bible, the Protestant movement took hold. It quickly diversified: Huldrych Zwingli in Zurich and, most influentially, John Calvin in Geneva built the Reformed tradition, emphasizing God's sovereignty and (in Calvin's case) predestination; the Radical Reformation (Anabaptists) rejected infant baptism and church-state union, and were persecuted by Catholics and Protestants alike; and in England the Reformation took its own path when Henry VIII broke with Rome (1534), producing the Church of England (Anglicanism), which kept much of the old order while embracing Reformation theology. The Reformers saw themselves as recovering the original Gospel from medieval accretions; the Catholic Church saw them as shattering the unity of Christ's church and mistaking novelty for return. Both readings are given here, and the enduring theological questions the Reformation raised, the authority of Scripture versus Scripture-with-tradition, faith alone versus faith formed by works and sacraments, are treated neutrally in this reference's theology deep-dives (justification; election), not settled here.