If the Devil takes a personal interest in harvesting your soul, you've either been very good or very bad. In rare cases, like that of the hero in this fire-and-brimstone thriller, you've been both. Such theological musing is inescapable when confronting 2005's first major action movie, whether one is disposed to take the subject matter seriously or not. Those who accept the film's treatment of redemption at face value, however, should immediately consult with their priest, rabbi, or imam.

According to Constantine, culled from the "Hellblazer" series of DC Comics and graphic novels, God and Lucifer have an ongoing bet over the souls of human beings. Their contest is regulated by strict rules that help maintain a state of equilibrium on the human plane. Neither side can violate the laws of free will, but they can do things that influence actions taken by their mortal playthings.

John Constantine (Keanu Reeves) has seen the fires of hell up close and wants to avoid spending eternity there. He's a kind of supernatural immigration officer, sending demons back to Hades if they break the rules. He hopes his duties, which entail exorcisms and a lot of special effects-laden fighting, will earn him enough points to guarantee salvation. On the down side, and the reason he's caught in limbo: he committed the mortal sin of suicide as a young man, driven to despair by his ability to see the demons and angels as they operate in the earthly realm.

Aggressive lung cancer has made his eternal fate a pressing issue. But God, represented by the angel Gabriel (Tilda Swinton), won't make an exception. Constantine is going to hell. Or so it would seem until increasingly bold forays by demons, following the discovery of a special weapon in the Mexican desert, suggest an ominous exodus from the underworld is in the offing. JC's special border patrol talents are needed more than ever.

He hooks up with a clairvoyant Los Angeles cop (Rachel Weisz) investigating the suicide of her twin sister. In an echo of last year's Collateral, in which an assassin (Tom Cruise) was driven around the City of Angels by Jamie Foxx’s cab driver, Constantine -- dressed in a black suit, thin black tie, and white shirt -- travels by taxi with an aspiring young occultist (Shia LaBeouf) at the wheel. Along with a couple of scruffy, doomed, sidekicks, he rubs shoulders with other interesting characters such as the proprietor of a literal den of iniquity (Djimon Hounsou), a natty Balthazar (Gavin Rossdale), and eventually Satan himself, limned by a hissing Peter Stormare.

The most practical lesson to be gleaned during a viewing of Constantine involves what to do when attacked by a demon. First, spritz water on it; second, curse at it; third, give it the finger. Following the hero's example, you must deal roughly with these beings. There's no place for politeness.

Reeves' monotone is ideal for the one-liners he delivers, and he's obviously comfortable playing post-modern savior figures. Weisz -- and Swinton in the pivotal role of the androgynous angel -- keep straight faces. Visual gags, like a billboard with the slogan "got faith?" in the background of one shot, add to the gloppy, although technically well-rendered, texture.

Rife with accessible mumbo-jumbo, to coin an oxymoron, Constantine is not inscrutable like The Matrix franchise. The premise is spelled out carefully and repeatedly so that the 15-year-olds packing theaters (despite the R rating) get it. And beneath the rings of absurdity, there's a degree of seriousness, especially if you credit an overheated notion of self-sacrifice that could conceivably convert impressionable members of the audience.

Constantine trivializes of course, yet it's respectful enough not to offend anyone with strongly held religious beliefs. Certainly those with a penchant for Mediaeval Catholicism (Mel Gibson?) will feel right at home. Teeming with Christian ideas and symbolism, it's Milton's "Paradise Lost" as a slick video game. While spurious theologically, cinematically speaking Constantine's troubled soul is worth fighting but not dying for. 

(Released by Warner Bros. and rated "R" for violence and demonic images.)