Lyric discussion by Door 

Cover art for My God Is the Sun lyrics by Queens of the Stone Age

It's pretty obvious what the speaker is saying- he's declaring the sun to be his god and seemingly asking it to "heal them", whoever they are. The lyrics may have no meaning, but it seems to be about ignorance, as kangus said. Along with what he/she has pointed out, I've got a quote from George Carlin here, talking about religion, that is not only relevant, but probably influenced this song-

"So rather than be just another mindless religious robot, mindlessly and aimlessly and blindly believing that all of this is in the hands of some spooky incompetent father figure who doesn't give a shit, I decided to look around for something else to worship. Something I could really count on.

And immediately, I thought of the sun. Happened like that. Overnight I became a sun-worshipper. Well, not overnight, you can't see the sun at night. But first thing the next morning, I became a sun-worshipper. Several reasons. First of all, I can see the sun, okay? Unlike some other gods I could mention, I can actually see the sun. I'm big on that. If I can see something, I don't know, it kind of helps the credibility along, you know? So everyday I can see the sun, as it gives me everything I need; heat, light, food, flowers in the park, reflections on the lake, an occasional skin cancer, but hey. At least there are no crucifixions, and we're not setting people on fire simply because they don't agree with us.

Sun worship is fairly simple. There's no mystery, no miracles, no pageantry, no one asks for money, there are no songs to learn, and we don't have a special building where we all gather once a week to compare clothing. And the best thing about the sun, it never tells me I'm unworthy. Doesn't tell me I'm a bad person who needs to be saved. Hasn't said an unkind word. Treats me fine. So, I worship the sun. But, I don't pray to the sun. Know why? I wouldn't presume on our friendship. It's not polite."

Song Meaning

Man, you could not be more clear, word by word it's exactly what I think!