Calvin, for example, although preferring beheading, had Michael Servetus burned alive as an anti- Trinitarian heretic.
After publishing these heretical ideas, Servetus was condemned by the Catholic Inquisition in Vienne,
and finally burned with his own books in Calvin's Geneva.
The Catalonian polymath and theologian Michael Servetus found numerous Quranic arguments to employ in his anti-Trinitarian tract,
Christianismi Restitutio(1553), in which he called Muhammad a true reformer who preached a return to the pure monotheism that Christian theologians had corrupted by inventing the perverse and irrational doctrine of the Trinity.