
A image (Ѻ) of a Spanish or Italian version of *Treatise on the Three Impostors*, showing Moses with his “horns”, Jesus with his cross and rays of sunlight (halo), and Muhammad, with his holy Quran, each of whom are dubbed “impostors”, in the said book, i.e. scammers who founded religions on false pretenses, or something to this effect.

A image (Ѻ) of a Spanish or Italian version of Treatise on the Three Impostors, showing Moses with his “horns”, Jesus with his cross and rays of sunlight (halo), and Muhammad, with his holy Quran, each of whom are dubbed “impostors”, in the said book, i.e. scammers who founded religions on false pretenses, or something to this effect.

In famous publications, Treatise on the Three Impostors is an apocryphal 13th century book said to have been written by Frederick II (1239), or later by Simon of Tournai (1130-1201) or Bernardino Ochino (1487-1564), wherein the divinity of divinity of Jesus, Moses, and Muhammad is denied, and each or dubbed "impostors", hence the term "three impostors".

Overview
In 1239, Frederick II is purported to have either denied verbally the divinity of Jesus, Moses, and Muhammad, declaring each of them imposters, and or to have published a book or treatise on such a supposition; the following is testimony to this:

“Frederick II, this pestilent king, a scorpion spitting out poison from the stinger of his tail, has notably and openly stated that—in his own words—the whole world has been fooled by three impostors, Jesus Christ, Moses, and Muhammad, two of whom died honorably, while Jesus himself died on the cross. Moreover, he has dared to affirm, or rather, he has fraudulently claimed, that all those who believe that a virgin could give birth to the god who created nature, and all the rest, were fools. And Fredrick has aggravated the heresy by this insane assertion, according to which no one can be born without having been conceived by the prior intercourse of a man and woman; he also claims that people ought to believe nothing that cannot be proven by the strength and reason of nature.”
— Pope Gregory IX (1239), address to monarchs

This resulted in the anonymous Treatise on the Three Impostors (aka The Atheist’s Bible), either written by Frederick II or Simon of Tournai (1130-1201) or Bernardino Ochino (1487-1564), which began to circulate (Ѻ) in the centuries to follow.

In 1770, Voltaire, published a response to the hoax treatise entitled Epistle to the Author of the Book of the Three Impostors (Épître à l'Auteur du Livre des Trois Imposteurs) (Ѻ), which contains one of his best-known quotations, "If god didn't exist, it would be necessary to invent Him."

In 2009, Georges Minois, in his The Atheist’s Bible: the Most Dangerous Book that Never Existed, argues something to the effect that the three impostors treatise never existed, and that Voltaire was the first to make a semblance of such a book. [1]

References
1. Minois, Georges. (2009). The Atheist’s Bible: the Most Dangerous Book that Never Existed (translator: Lys Weiss). University of Chicago Press, 2012.

External links
● Treatise on the Three Impostors – Wikipedia.