Because Gerard Butler has decided to give himself to the world of movies, the most pressing Gerard Butler-based question needing immediate address is this: which Gerard Butler do you want in your life?
You have two choices. You can try to figure out the meaning and purpose of The Phantom of the Opera/Katherine Heigl-wooing Butler, a neutered approximation of maleness stripped of all weaponry and not allowed to put round after round of bullets into anyone, or you can vote for the RocknRolla/300/Law Abiding Citzen GB who carves up his enemies, blows everyone to smithereens and rigs up murderous cell phones that will shoot you right in the head.
There's not much real choice when you think about it that way, is there? The man simply looks more comfortable when he's fake-murdering people rather than when he's fake-loving them. Lucky you, then, that in this story of real-life missionary Sam Childers, Butler gets to use the machine guns of the title with a fair degree of regularity.
Before that missionary work, in which he builds orphanages in the southern Sudan and rescues orphans from the ongoing war that otherwise turns them into sex slaves or child soldiers, you get to watch Childers' old life, the one where he was a bad, bad man. In the film's opening moments he's sprung from prison and, within about 36 hours, he has threatened his own wife (Michelle Monaghan), shot up heroin in the toilet of a biker bar, robbed people, shot at them and, in a feat of insane choreography, injected a car-driving dirtbag friend with speed from the passenger seat before knifing up a hitchhiker and leaving him for dead. It's like he's going for a gold medal in recidivism, only failing to commit mail fraud in the process.
Waking up just in time from this wild crime party, Childers becomes a born-again Christian, starts a construction business, builds himself a church, decides to become the preacher, feels called to Africa to help the orphans, goes there, builds an orphanage, comes home, bullies rich people for money, goes back, rescues a thousand orphans and picks up his machine guns to defend them from attack. This is not a turn-the-other-cheek kind of guy. He takes his Christian soldiering literally and, if you were in his biker boots, you'd probably seriously consider that option yourself.
There's nothing especially artful or subtle about this movie, but that was probably never the intention in the first place. The real-life Childers is a blunt man and so a blunt instrument of a film about him is sort of just what you'd expect. If director Marc Forster had wanted to make a documentary (you get to see lots of doc footage over the closing credits) then he could have done that just as easily, but then there'd be one less bruisery example in the Gerard Butler plus-column and possibly one more rom-com cluttering up theaters.
This must not be allowed to happen.