Rev. Tess Baumberger: The life and death of a Unitarian martyr

Rev. Tess Baumberger

On Oct. 27, 1553, a Spaniard named Michael Servetus was burnt at the stake in Geneva, Switzerland. Today, medical experts recognize him as the first to describe pulmonary circulation accurately, while theologians know him as one of the first to challenge the doctrine of the trinity, which explains his fiery death.

In life Servetus was a genius. At 13 he read Spanish, French, Greek, Latin and Hebrew, even though Hebrew was a forbidden language at the time. Later he learned Arabic in order to study the Koran. By 16, Servetus had read the bible and the works of the early church fathers in their original languages.

He was surprised to find no mention of the doctrine of the trinity — one God in three persons — in the earliest copies of the Bible. He knew the Inquisition in his country persecuted Jews and Muslims for refusing to accept that doctrine, seizing their property, exiling them — but that doctrine was not in scripture.  At 20, Servetus published “On the Errors of the Trinity.”  It caused an uproar. A year later he published a second book, “Two Dialogues on the Trinity.” It expressed his ideas more moderately, but the ideas were the problem. Targeted by the Spanish Inquisition, he fled, assumed a different name and went to medical school — hence his expertise on pulmonary circulation. 

Servetus was not Unitarian in the sense of believing Jesus was only human, but he was Unitarian in insisting on the unity of God. Servetus believed Jesus was the Son of God, born fully human and made divine later through a special favor from God. Servetus believed the Holy Spirit was simply God acting in humans, not a separate entity. These beliefs were a radical departure from church doctrine, but he refused to retract them.

From hiding, he corresponded with Protestant Reformer John Calvin under the pseudonym “Michael Villanovanus.” His letters were fierce, radical, but what landed him in trouble was his next book, “The Restoration of Christianity.” He sent Calvin a copy that had the initials “M.S.” on the cover, and Calvin finally realized his scrappy correspondent was Michael Servetus. Calvin called in the Inquisition. They caught Servetus in Lyon and sentenced him to death. The night before his execution, his jailers let him go for a walk – and later found the ladder he used to escape. They burnt him in effigy.

After his escape Servetus went straight to Geneva, straight into the church where Calvin was preaching, perhaps thinking he could change Calvin’s mind. Calvin had him arrested. His trial, in a town Calvin held in his palm, proceeded apace even though it was illegal to try a Spaniard in Switzerland. The court sentenced Servetus to death, refusing his request for death by beheading. Michael Servetus died the death of a heretic, burning slowly over green wood. Along with him Calvin burned what he thought were the only remaining copies of “The Restoration of Christianity.”

Servetus went bravely to his death. The linguistic, theological, and medical genius stayed true to his conscience to the very end. His story is important because as religious people, we sometimes need to say or do what we believe is right, even when it feels dangerous. We may not be burned at the stake, but we may be objects of ridicule, hatred and violence. The life and death of Michael Servetus shows us that if we have the courage to do what is right anyway, it can change the world.

The Rev. Tess Baumberger, PhD, is minister at Unity Church of North Easton, Mass. For more information about Unitarian Universalism please you will find links to all our churches. You can reach her at