actually the snake behind him in H. refers to jesus, but also the fact that both his parents were preachers. The song judith from the mer de noms album talks about how despite the fact that there is no god, no heaven no hell, that even in the throes of death she did not relinquish her faith that there was something else there for her, and that she did it without questioning, without her eyes open.
The piss to wine is a reference to jesus. And to the lies (in mythologies of all types, the snake is a symbol of a liar etc) spread by those who follow the lies of christianity.
In addition, the title H. is also lauded to be in relation to the quote by Karl Marx, that religion is the opiate of the masses. H, as everyone would know refers to heroin, the most widely available illicit opiate.
Almost every one of Maynards pieces is multi leveled and faceted. To make definitive judgments that it is specifically about one thing and not the other is to avoid the whole reason that there aren't any lyrics in the album sleeves, it is because people will make what they will, and take away what they want from each piece of artwork.
One fan told maynard that the song sober really helped him quit using opiates and get straight, and yet the song is wholly about asking the question why do we need to be sober, cant we just be smashed all the time.