It's the classic trap of the street evangelist. You commend someone who says they're basically good, then tease out evidence of some modest sin, and finally whip out that verse about how the wages of all sin is death (Romans 6:23).

Perhaps almost implausibly, this is the basic premise of Bastille Day, James Watkins' one-name-on-the-poster vehicle for Idris Elba, who post-Luther is now seeking to establish himself as a genuine big screen action lead. Elba plays Sean Briar, some sort of cop/secret agent type in Paris, whose backstory never seems particularly important, and who picks up American pick pocket Mason (Cinderella's Prince Charming, Richard Madden) when he's implicated in an apparent terror attack. Yes - a terror attack in Paris, and yes - it does feel a bit too soon.

With its allusions to Anonymous-style cyber activism and occasionally artsy camera work, Bastille Day sometimes thinks it's smarter than it is. In fact it's a fairly run-of-the-mill action caper, occasionally elevated by some superior action sequences (one rooftop chase in particular) and intricate pickpocket hook, but held back by a clunky, cheese-topped script and some particularly phoned-in performances. While Madden is actually pretty engaging as the film's understated focal point, its star is so wooden you're left wondering if 'Elba' is a new kind of IKEA table.

Screenwriter Andrew Baldwin utilises a couple of decent plot twists to keep things interesting, but for me the most intriguing element of the film is the story of Mason, the man who finds that his fairly low-level 'sins' have led him stumbling into almost irredeemable territory. He's a character who keeps telling himself he's going to leave his life of petty crime behind and turn his life around, when in fact it's careering out of control. Before long, he's realised that he can't save himself without help, and when his shot at personal redemption comes along (in a church, naturally), there's a knowing element of theological literacy involved; he both has to make the right choice out of his own free will, and depend on the help of a sort of higher power too.

That's not to say that Bastille Day is a Christian-themed, or even a wholesome film. Alongside some needlessly coarse language, there's a Gratuitous Naked Lady in the very first scene, (and don't expect it to win any gender equality awards for anything that follows thereafter). It is however, a pretty fantastic illustration of how sin deceives us into thinking we're in control, before pulling the rug from under us and reminding us that we can't save ourselves. That in turn is a great explanation of why humanity needs a saviour, rather than a swaggering, gun-toting action hero.

Martin Saunders is a Contributing Editor for Christian Today and the Deputy CEO of Youthscape. You can follow him on Twitter: @martinsaunders