
Hungarian-born American polymath John Neumann, a life-long secular agnostic, during his last 8 months of existence, after being diagnosed with bone or pancreatic cancer, called a priest to his side, expressing great fear of death, and therein took vows expressing his belief in the existence of god, i.e. became a theist, so to side with Pascal’s wager, and not have to suffer the possibility of eternal damnation, as he saw things in his mind.

Hungarian-born American polymath John Neumann, a life-long secular agnostic, during his last 8 months of existence, after being diagnosed with bone or pancreatic cancer, called a priest to his side, expressing great fear of death, and therein took vows expressing his belief in the existence of god, i.e. became a theist, so to side with Pascal’s wager, and not have to suffer the possibility of eternal damnation, as he saw things in his mind.

In geniuses on, Neumann on god refers to the paradoxical nature of the religious beliefs, particularly in respect to the question of the god's existence, of Hungarian-born American polymath John Neumann (1903-1957), the last of the last universal geniuses, who was raised in an ecumenical non-serious Jewish family, who defined themselves as Jewish, for reasons of "tradition", who, in his first marriage, nominally converted to Catholicism, albeit presenting himself as agnostic throughout his days to his friends and associates, but who in his last months on his death bed, Apr/May 1956 to his last day of existence on 8 Feb 1957, had Roman Catholic priest Anselm Strittmatter stay by his side, wherein he expressed great fear of death, and asked to have Pascal's wager administered to hims so that he wouldn't have to endure the possibility of eternal damnation.

Religion
Neumann was born into a Jewish family with “ambivalent” religious attitudes; his family was so ecumenical that his family put up a Christmas tree, exchanged gives, and sang Christmas carols each year with their German governess, while also maintaining equal secular observance of the major Jewish holidays. Once Johnny’s brother Michael asked his father Max Neumann why the family considered itself Jewish when it did not observe the religion seriously? Max’s answer was: “tradition”. This religious confusion, according to William Poundstone, “would follow von Neumann throughout his life”, inclusive of a nominal conversion to Catholicism at the time of his first marriage, stitched together with an essentially agnostic belief system stance [1] Neumann’s friend Edward Teller commented that whenever Neumann was tempted to curse, he would refrain himself and joke, “Now I will have to spend two hundred fewer years in purgatory.” [1]

Last days | Pascal's wager
In the spring of 1956, at the hospital, while in his last 18-months dereacting (dying) from cancer, Neumann invited Anselm Strittmatter (1894-1978) (Ѻ), a well-educated (Ѻ) Roman Catholic priest who could discuss classical Rome and Greece, to visit him for consultation, who thereafter he began to see regularly. During these visits, Neumann expressed great fear of death. To his visitors, he despaired that “he could not visualize a world which did not include himself thinking within it.” [2]

Neumann recited in Old Latin passages about judgment, right and wrong, and freedom:

“When the judge his seat hath taken .. what shall wretched I then plead? Who for me shall intercede when the righteous scarce is freed?

Neumann told the priest that Blaise Pascal, in section 233 of Pensees, had a point, referring to Pascal's wager, commenting something to the effect of: [2]

“So long as there is a the possibility of eternal damnation for nonbelievers it is more logical to be a believer at the end.”

Neumann, in short, he sided with Pascal about betting one's afterlife on belief or nonbelief in the existence of god.

Subsequently, so to not lose in the wager, Father Strittmatter administered the last sacraments to him. [3] To his mother, who was also dying from cancer during this period, he expressed the following similar view: [2]

“There probably has to be a God, because it is more difficult to explain if there is than if there isn't.”

Some of Von Neumann's friends, having always known him as "completely agnostic", believed that his religious conversion was not genuine since it did not reflect his attitudes and thoughts when he was healthy. As Dutch-born American physicist and science historian Abraham Pais reports: [4]

“He had been completely agnostic for as long as I had known him. As far as I could see this act did not agree with the attitudes and thoughts he had harbored for nearly all his life.”

Even after his conversion, Father Strittmatter recalled that von Neumann did not receive much peace or comfort from it as he still remained terrified of death.

References
1. Poundstone, William. (2011). Prisoner’s Dilemma (§: The Child Prodigy, pgs. 12-). Random House LLC.
2. (a) MacRae, Norman. (1992). John Von Neumann: the Scientific Genius Who Pioneered the Modern Computer, Game Theory, Nuclear Deterrence, and Much More (God, pg. 43; deathbed, pgs. 378-79). American Mathematical Society.
(b) Pascal’s wager – Wikipedia.
3. Halmos, P.R. (1973). “The Legend of von Neumann”, The American Mathematical Monthly, 80(4):382-94.
4. Pais, Abraham. (2006). J. Robert Oppenheimer: A Life (pg. 109). Oxford University Press.