Radical Reformation

Radical Reformation names the loosely related sixteenth-century movements that broke with both the Roman Catholic Church and the newly established Lutheran and Reformed churches, judging the mainstream Reformation itself incomplete. Historians commonly group its many local currents into three broad types: Anabaptists, spiritualists, and evangelical rationalists.¹ The three currents differed sharply from one another, but each rejected the magisterial Reformers’ own settlement of a state-sanctioned church, and two of them are tied together directly by Reformed theologians describing the movement’s excesses.²³

Anabaptists

The Anabaptists trace to Conrad Grebel’s circle of Ulrich Zwingli’s own followers, who broke with him over infant baptism in Zurich in January 1525 and gathered congregations of the voluntarily committed, separated from civil office, oath-taking, and the sword.⁴ A militant faction’s seizure of the German city of Münster in 1534, crushed the following year, gave the whole movement its most notorious reputation; the former priest Menno Simons reorganized the survivors around nonviolence and voluntary discipline, the “gentler Anabaptism” that gave the Mennonites their name and became the movement’s lasting form.⁵

Spiritualists

A second, more erratic current traced true religion not to gathered congregations but to an inward, immediate revelation independent of the Bible. Andreas Karlstadt, once Martin Luther’s own colleague at Wittenberg, gave it his support when the self-styled prophets Nicholas Storch and Thomas Stübner arrived in Wittenberg during Luther’s confinement at the Wartburg, denouncing learning and church institutions and teaching that “all reliance was to be placed on the inward light, or supernatural guidance of the Spirit.”⁶ Thomas Müntzer carried the same principle furthest, applying to himself and his followers the claim that they alone were the true, inspired church, entitled to rule in church and state and to exterminate all who opposed them; the “grievous and long-continued oppression of the peasantry” fed the resulting revolt across Germany, Switzerland, and Holland, and Müntzer himself died on the scaffold after the Peasants’ War of 1525.⁷

Karlstadt afterward joined Caspar Schwenkfeld, a Silesian nobleman (1490-1561) who had at first supported the Reformation before separating from Lutherans and Reformed alike. Schwenkfeld held that Christ’s own human nature was formed of the substance of God rather than being a creature, and drew from that Christology a doctrine of salvation as a purely inward, substantial communication rather than a forensic verdict: “he denied justification by faith as Luther taught that doctrine… he said that we are justified not by what Christ has done for us, but by what He does within us.”⁸

Later writers in the same line, Valentin Weigel, the physician-alchemist Paracelsus, and the mystic Jacob Boehme, carried the inward-light principle, “that the inner word, and not the Scriptures, was the source of true knowledge,” into the seventeenth century.⁹

Evangelical Rationalists

A third current, centered on the Italian Fausto Sozzini and the Racovian Catechism his followers produced in Poland, denied the Trinity and Christ’s eternal deity outright, holding him to be a mere man exalted by God rather than God the Son incarnate, a psilanthropite Christology Reformed writers classed alongside the ancient Ebionites and Paul of Samosata.¹⁰ Centered at first on the “then tolerant kingdom of Poland,” Socinianism reached England only after the turn of the seventeenth century, through what one historian of the movement calls Holland’s role as a “gateway” for its spread.¹¹ English opponents summarized its errors as a denial of Christ’s satisfaction and the Trinity together: “they deny Christ’s satisfaction, and so overthrow the foundation of our faith… they deny the Holy Trinity, and so take away the very Object of our Faith.”¹²

Reformed Assessment

Reformed theologians have most often assessed the Radical Reformation’s currents by what they share rather than treating each in isolation. Louis Berkhof traces the Anabaptist and Socinian departures to a single underlying antithesis of nature and grace inherited from medieval Rome: “Anabaptism and Socinianism suffer from the same antithesis, but with the distinction that the former exalts grace at the expense of nature, while the latter exalts nature at the expense of grace.”³ Herman Bavinck locates the movement’s shared political radicalism in its rejection of any state role in religion at all: “already in the sixteenth century some Anabaptists and Socinians insisted that the government should abstain from all intervention in matters of religion and specifically from the punishment of heretics,” a position the magisterial Reformers themselves did not hold, though later Protestant states gradually adopted it in practice.²

Related Doctrines

References

“Radical Reformation,” Wikipedia, accessed September 16, 2026, https://en.wikipedia.org/wiki/Radical_Reformation. ↩
Herman Bavinck, Reformed Dogmatics: Abridged in One Volume, ed. John Bolt (Grand Rapids: Baker Academic, 2011), chap. 21, “The Church as a Spiritual Reality.” ↩ ↩²
Louis Berkhof, Systematic Theology (London: Banner of Truth Trust, 1969), 444. ↩ ↩²
Bavinck, chap. 21, “The Church as a Spiritual Reality.” ↩
Bavinck, chap. 4, “Revelation.” ↩
Charles Hodge, Systematic Theology, vol. 1 (New York: Charles Scribner and Company, 1871), chap. 4, “Mysticism,” 81. ↩
Hodge, 1:80-81. ↩
Hodge, 1:82-83. ↩
Hodge, 1:83-84. ↩
Archibald Alexander Hodge, Outlines of Theology (New York: Robert Carter and Brothers, 1879), chap. 6, Q. 13. ↩
H. John McLachlan, Socinianism in Seventeenth-Century England, 2, quoted in Jonathan Elliot Swan, “The Eternal Son of God in Eighteenth-Century England,” in “‘The Fountain of Life’: John Gill’s Doctrine of Christ’s Eternal Sonship” (PhD diss., The Southern Baptist Theological Seminary, 2021), 21-80, at 34. ↩
Francis Cheynell, The Rise, Growth, and Danger of Socinianisme, 1, 24, quoted in Swan, 34. ↩