Of all the factors that led to the Protestant Reformation and the Radical Reformation, nothing was as revolutionary as the translation of the Bible into the language of the people and the development of new printing technologies starting in the 1400s.

The combination of the two made Christianity’s foundational document, long the province of clergy and academics, accessible to everyone.

For more than a millennium, the Scriptures were available only in Latin (with a few exceptions), the language of the Roman Catholic Church. Reproduction, such as by handwriting, was laborious and expensive, which meant that few copies were available.

But thanks to reformers who translated the Bible — and to Gutenberg’s printing press, which made mass production possible — common people were able to discern biblical teachings for themselves, rather than having to rely exclusively on being told what to believe.

As a result, the ancestors of today’s Mennonites, Amish and Hutterites became keenly knowledgeable of the Bible’s contents. That’s why they challenged the religious and civil leaders when the Anabaptists saw their positions, such as infant baptism, as unscriptural.

Some Anabaptists went to silly extremes. Some argued that believers should be baptized at the age of 30, as Christ was. One group dressed in swaddling clothes and babbled like babies to become the “little children” Christ promised would enter the kingdom. None other than Conrad Grebel maintained that the Lord’s Supper should be observed only in the evenings, because that’s when the bread was broken and cup shared in the upper room prior to the crucifixion.

Yet other Anabaptists recognized that Scripture was not enough. It provides knowledge, Ludwig Haetz­er said, but knowledge “which does not reform.” The leading of the Holy Spirit was also needed. Noting that the Bible could be physically “blotted out,” Hans Denck wrote, “The Holy Scriptures I hold above all treasures, but not as high as the Word of God, which is living, powerful and eternal.”

Denck was an influential leader of the South German Anabaptists, so much so that other Protestants called him “pope,” “abbot” and “rabbi” of the fledgling movement. He was also a spiritualist, stressing the “inner word” or “inner voice” as well as the external written word.

“If God were not to do more — every moment and hour — than what can be known through his letter alone, how mighty, good and just he is, he would remain unknown for a long time,” Denck said.

This approach to Scripture distinguished Anabaptists from the rest of Protestantism, which proclaimed faith based solely on the Bible, or sola Scriptura. Anabaptists, however, emphasized sola Christus — Christ alone. Menno Simons upheld that belief with his personal motto, 1 Cor. 3:11: “For other foundation can no man lay than that is laid, which is Jesus Christ.” This echoed the credo of Denck, who died in 1527, nine years before Menno left the Catholic Church: “No one may truly know Christ except one who follows him in life.”

One of Denck’s concerns was bibliolatry — worshiping Scripture as believers are supposed to worship God. He compared the Bible to correspondence from a dear friend. The letter testifies to the friend’s importance in the recipient’s life, and so it is kept and valued and reread. But the letter is not the friend.

The Spirit’s presence was important because the Bible can be a confusing and confounding book. In one pamphlet, Denck noted 40 contradictions in the Bible, such as “For judgment I came into the world” (John 9:39) and “I am not come to judge the world but to save the world” (John 12:47). Such instances don’t invalidate the Bible, but they do mean that the reader needs help making sense of them, Denck said, citing 2 Peter 1:20-21: “First of all you must understand this, that no prophecy of Scripture is a matter of one’s own interpretation, because no prophecy ever came by human will, but men and women moved by the Holy Spirit spoke from God.”

Of course, the Anabaptists embodied that. They used the Bible, just as the Catholics, Lutherans and Reformed did. But the Holy Spirit led them to different understanding and made change possible and created today’s church.

Rich Preheim is a writer and historian from Elkhart, Ind.