He who constantly looks towards heaven will break his nose.

It's an old Czech proverb, according to Michael Marianek, a heaven-fancier. It's his last word on his idea of heaven, before he turns over to tan his back.

Last year, Glasgow-based artist Stephen Skrynka bought an old Ford Cardinal hearse and installed a sunbed inside it. He took it out on the streets and offered a deal: a tanning session in exchange for customers' thoughts on heaven. His CCA exhibition My Idea of Heaven is more than a record of the result.

It's an extraordinary concept. UV light inside a death cab. There's a noirish filmic quality on the screens in the gallery. Streaks of bright spill out of the coffin-shaped sunbed into the dark space. The notion of sun, warmth, holidays, youth - radiation to make you look good while secretly killing you - enclosed in a moving burial chamber. In the limbo between life and death, what are our hopes and beliefs?

"Heaven's a malleable form," says one man. "Colours soft, very big. Each person gets on with their own thing without hindrance."

Different takes on barter, consumerism, appeal to Skrynka. His project before this was a taxi in which, instead of money, passengers were asked to perform. Skrynka as cabbie decided how far their act would take them. Journeys from the city centre to Easterhouse or Shawlands were "paid for" by songs, stories, the preparation of meals (on camping stoves) and, inevitably, sexual exhibition. In My Idea of Heaven, customers get a tan in exchange for deeply personal notions of God, heaven and heavenliness. The upshot is by turns funny, sexy, sad and clever.

Skrynka has been tapping into a new mood in contemporary art for some time. This year's Turner shortlist is the most political for years. On the way out is the artist's obsession with the self. With what it's like to be a creator, an individual. The "black box of consciousness" - the inability to escape our own minds - is giving way, momentarily at least, to the artist looking out instead of in.

This is an exhibition for the age of Dawkins. Squeezed between the Hitchens and Dale Dennetts on one side, the Bushes and bin Ladens on the other, our personal notions of the hereafter have become a gold-standard commodity. It's the stuff of dissension, of wars.

"The angels have all come down," says one woman. "They've all come down."

"I definitely think heaven exists," says one screen, while another says: "It does not."

But the interviewees, temporarily trapped in a disorienting space, go beyond simple statements of belief, of dogma. They begin to day-dream about the celestial.

"We live by creating little heavens. Ideas that we like, that make us feel comfortable, at ease," offers Jimmy Bonachea Guerra from Cuba, an artist, it turns out, himself. Other clients are simply people who passed by wherever the tanning-hearse happened to be stationed.

"I'd like heaven to be like sex," breathes a youngish Frenchman. "Yes, that's it. Something very strong and very beautiful. I think of sex."

The visitor finds himself making comparisons, noting how thoughts on death and redemption are political, culturally bound. Interesting that it's a Czech who is most convinced of heaven's existence - a country whose Velvet Revolution was fuelled by Catholicism. Younger tanners have individual little Shangri-Las. "You can do what you like. Nobody bothers you."

You'll not find answers to metaphysical questions in My Idea of Heaven. I doubt that was ever Skrynka's intention. What you do find are people musing, wondering, questioning their own beliefs, like you and I do. This is not simply an intellectual pursuit, it's a visual and creative one.

Walking into the darkened space is like entering a tomb. The sunbed used for the interviews sits at the centre, like a sarcophagus. The hard, white light it emits is reminiscent of near-death experiences - the light beyond that both beckons and repels. On the screens are close-ups of faces, but you become aware how far some people were prepared to go for the project. A few have stripped off, enjoying the exhibitionism. Others cover up, embarrassed. The correlation between their physical demeanour and their personal philosophies is intriguing. It is a fascinating, humane venture. "Heaven is everything. Heaven is nothing."

My Idea of Heaven is at the CCA, Glasgow, until tomorrow.