Unknown if it is true or not there is a story in which Euler convinces a French Philosipher that God did indeed exist.
This story could be an urban myth, but in reality Euler did have other published proofs that God existed.
The story is as follows: Once at the court of Catherine the Great Euler met a French philosopher named Denis Diderot.
Diderot was a convinced athiest, and was trying to convince the Russians into athism also. Catherine was very annoyed by this
and she asked for Euler's help. Euler thought about it and when he began a theological discussion with Diderot, Euler said:
" (a+b^n)/n = x, therefore God exists" Diderot was said to know almost nothing about algebra, and therefore returned to Paris.