Norman Greenbaum is Jewish. He is, in fact, currently, a practicing Jew.
If you're having trouble recognizing him, that's ok. You probably know his song though: "The Spirit in the Sky." Yup. That's him. See, that's where things get tricky. And we quote:
Never been a sinner, I never sinned
I got a friend in Jesus
So you know that when I die
He's gonna set me up with the spirit in the sky.
Problem 1: Yeah, the song is in your head. Sorry. Problem 2: Wait, he's a practicing Jew and he wrote that? Apparently...
Greenbaum, for his part, says he was really into gospel music at the time and wanted to try to do his own version of it. And since gospel is all about the J-man, well, there ya go. Do non-Jews write music about Jewish stuff? Actually, yeah, all the time.
George Friederic Handel, for example. He of The Messiah fame (y'know, Hallelujah chorus? Yeah, we know. In your head. Sorry). Well, along with that big hit, Handel also wrote Oratorios based on Samson, Esther, Joshua, and Solomon.
So if you think about it that way, a devoted Jew writing a hit song about his devotion to Jesus makes quite a bit of sense, right?
Yeah, we know, we're not really buying it either.