February 26, 2023

Post Tenebras Lux (After Darkness, Light)

We Are Reformed

The phrase “Post Tenebras, Lux” (After darkness, light) was a rallying cry of the Protestant Reformers during the 16th century. It was used to symbolize the hope and optimism of a new era of Christian faith, following the darkness and corruption of the medieval Roman Catholic church.

The phrase first appeared on a medal that was struck in 1550 to commemorate the founding of the Protestant Academy in Geneva, Switzerland. The Academy was established by John Calvin, one of the most influential leaders of the Reformation, and became a center of theological education for Protestants throughout Europe.

Calvin used the phrase “Post Tenebras Lux” to express his belief in the power of God’s grace to overcome the darkness of sin and to bring salvation to all who believe in him. In his Institutes of the Christian Religion, Calvin wrote, “Christ, the true light, by whom the darkness of the world was dispelled, now shines forth in his church, and enlightens all who truly believe in him.” 1

Christian Reformers saw themselves as agents of this new era of light and knowledge. They believed that the medieval church had become corrupted by human traditions and practices that were not based on the authority of scripture. They sought to return to the pure teachings of the Bible and to reform the church according to its original principles. 2

Post Tenebras Lux became a powerful symbol of the Reformation, and it continues to be used by Protestants today as a reminder of the hope and light that can be found in Christ, even in the midst of difficult times. It speaks to the enduring legacy of the Reformation and the ongoing need for reform in the church.

Post Tenebras Lux is the rallying cry of Protestant Reformers, expressing their belief in the power of God’s grace to overcome the darkness of sin and to bring salvation to all who believe in him. It remains a powerful symbol of hope and light, reminding us of the enduring legacy of the Reformation and the ongoing need for reform in the church. 3


  1. Calvin, John. Institutes of the Christian Religion. Book 4, Chapter 1, Section 4. []
  2. McGrath, Alister. Reformation Thought: An Introduction. Wiley-Blackwell, 2012. []
  3. Noble, Thomas F. X. The Protestant Revolution: From Martin Luther to Martin Luther King Jr. HarperCollins, 2007. []

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