The Jesuit motto “ad maiorem Dei gloriam” (“for the greater glory of God”) is the obvious source of the title of this well-meaning but heavy-handed treatment of the Cristero Revolt against the liberal Mexican government during the late 1920s. There’s a hagiographic tone to the film, which at nearly two-and-a-half hours strains for epic sweep but gives itself over to historical oversimplification and pious melodramatics.

The film’s perspective on the event is utterly unambiguous. The government of President Plutarcho Elias Calles (played by Ruben Blades), who took power in 1924 under the revolutionary constitution of 1917 (and later founded the long-dominant political party, the PRI) was brutal and dictatorial, and showed its character in its suppression of the Catholic Church in 1927, spurred by the president’s own atheism. That action led to spontaneous uprisings against the secular regime on the part of pious believers who took up arms on behalf of the ecclesiastical order, but who ultimately were undercut by pragmatists in the Church. They reached a compromise with Calles that speeded the defeat of the Cristeros while winning them little in return.

The reality, of course, was rather more complex than the black-and-white portrait drawn here. Calles was undoubtedly an unbeliever inclined to socialist ideas and quick to employ harsh measures, portrayed here as simply an oily, unscrupulous villain—a characterization Blades etches nicely. But the actual Calles was, after all, trying to reform an economic system that was class-based and inequitable, and he had to deal with diplomatic intervention from the North, primarily concerned with U.S. oil interests in Mexico—a matter touched on glancingly here in the person of American Ambassador Murrow (Bruce Greenwood), appointed to handle the delicate situation by President Coolidge (Bruce McGill, who frankly seems too voluble for the role).

On the other hand, the Cristeros weren’t simply the faithful idealists shown here; the movement was led by members of the old socio-economic elite who felt threatened by the change of government, and some of the fighters were little better than bandits. Nor was the Church composed merely of the sort of selfless priests shown being killed by Calles’ inevitably thuggish soldiers—most notably the saintly Father Christopher, played with gentle fragility by Peter O’Toole, no less. In reality many ecclesiastics were in league with the oppressive ruling class, and religion was used by many Cristeros as a cloak for their more mundane motives for fighting.

In any event the historical context is employed primarily as a backdrop for personal stories, presented in a very broad fashion. Some are handled rather sketchily—like subplots involving rough but heroic rancher Victoriano Ramirez, known as El Catorce (Oscar Isaac), the priest-rebel Father Vega (Santiago Cabrera), whose character is much sanitized here, or the lovely Adriana (Catalina Sandino Moreno), who represents the women’s groups that smuggled guns to the rebels, which really get no more attention than the time given to Calles.

But two characters hold the spotlight throughout. One is Enrique Gorostieta Velarde (Andy Garcia), the ex-military man unhappy in his position as a soap manufacturer who’s persuaded to mold the Cristeros into an effective army. The screenplay rightly portrays him as a proponent of religious freedom, rather than an ardent Catholic, who accepted the post largely out of a desire to return to the field and for the large salary the movement’s elite backers offered him. But it creates an arc that takes him from what might be termed a benign agnosticism to full-fledged commitment to the ideals of his troops. And it fancifully connects his transformation with the second major personal story, of young Jose Sanchez del Rio (Mauricio Kuri), a boy who joined the movement, was captured by government troops, and executed. (The Church later declared him a martyr, and he was beatified by Pope Benedict XVI as recently as 2005.)

The script follows the hagiographic testimony about Jose’s life by Father Marcial Maciel closely, with a portrayal of his torture and execution that comes close to being a passion play. But it transfers his connection with another Cristero general, Prudencio Mendoza (including the account of his decision to give his horse to Mendoza in battle, although it led to his capture), to Gorostieta, making the lad the engine of the leader’s embrace of Catholicism. It also sees fit to add an utterly fictional conclusion to Jose’s death, with Gorostieta arriving moments too late to prevent the execution but promptly taking vengeance on the perpetrators. (The material about Jose’s father—here portrayed by Nestor Carbonell as a government official who reluctantly allows the recalcitrant boy to be killed—is also a melodramatic embellishment.)

The effect of all this is that “For Greater Glory” simplifies what was actually a fascinatingly complicated historical episode into something akin to a Catholic polemic. As such it should appeal to the faithful searching for an inspiring message, but it will be a disappointment to most others, especially because the unsubtle execution is in line with the approach. Given the many plot strands, director Dean Wright is more ringmaster than anything else, but he manages the battle sequences (including a train takeover) professionally, and together with cinematographer Eduardo Martinez Solares and editor Richard Francis-Bruce, delivers some lovely images and a decent pace.

Unfortunately, the actors are allowed little but broad brush strokes. Blades’ smooth villainy is contrasted with Garcia’s equally slick benevolence, but he’s asked to deliver a performance made up mostly of riffs with his cigars, heartfelt speeches to the troops and saccharine one-on-ones with Kuri, who’s notable mostly for his perpetually beatific smile. (As the general’s wife, Eva Longoria has little more than a cameo.) O’Toole, looking terribly feeble, is positively ethereal as the good-hearted priest whose execution serves as a model for Jose. For the rest, the cast go through their expected paces in the fashion of the crowds one finds in docu-drama mini-series.

In the end, though, while it might serve as an uplifting bit of hagiography for Catholic church groups, the film lacks the nuance and narrative sophistication to appeal to a wider audience.