I don't believe so...
Lex Luthor is depicted as a Nietzschean atheist in comics, although he is rarely (if ever) overtly identified by name as such.
The 1980s live-action television series Superboy portrayed a college-age Lex Luthor as an Episcopalian Protestant who enters an Episcopalian monastery as a monk in response to a lab accident that renders him bald.
And more from the site:
Clearly Luthor is not an adherent of any organized religion. However, Elliot S! Maggin, an observant Jew who is one of Superman's most popular and influential writers, has stated that Luthor is a non-observant Jew. Given Lex Luthor's utter disinterest in traditional organized religion and moral value systems, it is not surprising that his character never refers to any religious upbringing or religious ethnicity.
There seems to be little printed textual support for identifying Luthor as Jewish. But the theory certainly is plausible in a world where many of history's real-life brilliant world-changing atheists (or agnostics) have been Jewish, including Albert Einstein, Sigmund Freud, Karl Marx, Franz Kafka, Noam Chomsky, etc. (The obvious difference, of course, is that Luthor is evil while these other individuals, regardless of whether or you agree with them or not, were not evil.)
So whilst a contemporary writer may frame him as a non-observant jew, there's no evidence anywhere of this origin, or any real religious indications. Except in the live action Superboy, where he joined a bunch of episcopalian monks but that had Superboy fighting mormons with lasers (?) so I'm not sure it should be followed.