The article presents, on the example on Giulio Cesare Vanini (1585–1619), the consequences which those who were recognized as atheists faced in the early modern era. And the consequences were: exile, imprisonment, torture or death. In the times of Vanini every case of denying or undermining Christianity, especially Catholicism, was dubious. The worst of them was atheism which by the defenders of faith and the Roman Catholic Church was often regarded as a characteristic of a person who did not respect morality, surrendered to criminal tendencies, was crazy and insane, while atheism itself was treated as a criminal act. Vanini was sentenced to death at the stake due to the accusations of atheism. Their basis laid in the contents of his two works: Amphitheatrum Aeternae Providentiae Divino‑Magicum released in 1615 and De Admirandis Naturae Reginae Deaeque Mortalium Arcanis published a year later. As indicated in the article, the interpretation of the works very often influenced the fact that they could be recognized as scandalous and threatening and that the author was sentenced to death, although the content very often was simply controversial or ambiguous. The article also shows a brief survey of judgments and opinions concerning Vanini which arose from the 17th to the 19th century. From among the participants in the discussion, the views of Pierre Bayle’s deserve particular attention. He attempted to describe atheism without recognizing it as a flaw, guilt, sin or criminal trespass of a human. He believed that atheism was the result of the imperfect and mistaken human reasoning, and that a man leaning toward such ideological beliefs may still live according to moral principles. This was due to his belief that moral values are universal and independent of religion. However, as it is stated in the article, among the atheists there was no shortage of the ungodly, the sacrilegious, traitors, those who morally deprave and scandalise, with Donatien Alphonse Francois de Sade (1740–1814) as the most famous of them.