Jimmy Christ
Nobody knows the pain I feel
From an old rugged cross
Or on a movie reel
When I sit there all alone
And my thoughts I can't conceal
Rhyming every word as if it
Wasn't really real
Jimmy Christ
He's been produced
And he's been spliced
He's been crucified
Do you think
He should be denied? 

And finally, Whin's comment:

According to Johnny Rogan, Gene did three songs for the movie American Dreamer.

Jimmy Christ is an outtake. It clocks in at a brief 1:33, opens and closes with harmonica - typical Gene format.

I've not seen the movie so I don't know how the lyrics might fit.

Either way, the song could easily be Gene describing himself.