Keep your head down if you venture into the theater this week. The bomb-throwers are out in force — and they’re lobbing grenades in both directions.

Opening head-to-head last weekend, David Zucker’s liberal-bashing An American Carol and Bill Maher’s faith-skewering Religulous are pretty typical examples of what passes for reasoned dialogue in American culture today — which effectively means smug, cheap shots, tasteless shock tactics, sound bites over substance, mind-numbingly one-sided polemics, and a complete dearth of self-critical thinking.

Zucker, a longtime Hollywood satirist with a résumé that includes Airplane!, the Naked Gun movies and a couple of Scary Movie sequels, is a self-described “former liberal Democrat turned conservative Republican.”

An American Carol is his election-season riposte to Michael Moore’s guerrilla documentary agitprop. That’s the same genre used by Maher, a dogmatic agnostic scathingly contemptuous of religion, as the vehicle for his most recent attack on faith.

To the faithful on either side, the ends may justify the means.

If watching a bumbling terrorist cell (all named Muhammad Hussein) send a clueless suicide bomber on a slapstick out-of-control bicycle ride that ends with the bomber spinning through the air before smashing onto a car, and then blowing up along with a fellow jihadist who pulls the pin strikes you as irreverently hilarious, you might enjoy An American Carol.

On the other side, Religulous offers footage of popes and bishops intercut with garishly dressed rock stars or mushroom clouds, ambush interviews with subjects ranging from average Joe Sixpacks to deranged fringe figures, and a smattering of uncritically regurgitated anti-religious talking points that may titillate and flatter self-styled free thinkers.

Neither film withstands much critical thinking, although Religulous makes shrewder use of genre and rhetoric to get its point across. Truth may or may not be stranger than fiction, but satirizing Michael Moore with a look-alike actor is easier to see through than satirizing the real beliefs of real people.

After all, whether or not Michael Moore hates America, we know he didn’t actually agree to produce a training video for al-Qaida, like American Carol’s Michael Malone (Kevin Farley). The people Maher talks to really hold the beliefs they profess, ranging from the commonplace (biblical literalism, including young-earth creationism and the story of Jonah) to the bizarre (a cult leader who professes to be Jesus reincarnated and a Holocaust-denying rabbi).

Religulous uses humor more effectively than American Carol: for example, a riff on Dickens, in which Malone, an American Scrooge who hates the Fourth of July instead of Christmas, is visited by the ghosts of John F. Kennedy, General Patton and George Washington.

The problem is that satire is inherently skeptical and reductive; it is a tool for tearing down, not building up. Satire can have an implicit positive message, but American Carol goes awry by articulating its patriotic message in an overtly preachy way.

Religulous is preachy too, but since its skeptical message is purely reductive, it doesn’t risk sounding credulous. That doesn’t mean it isn’t credulous — only that the knowing tone doesn’t give the game away.

Maher uncritically tosses out bogus talking points culled from anti-religious sources without apparently making any effort to check his facts. At one point, the film throws out a hoary list of supposed parallels between Christ and the Egyptian god Horus, in which Egyptian mythology is blatantly rewritten in the image of Christ — much as some atheists claim the evangelists rewrote Christ’s life to match Old Testament prophecy.

Among the spurious claims with no basis in Egyptian mythology: Horus was virgin born (Isis was a widow, not a virgin, who conceived Horus through magical intercourse with her dead husband Osiris); Horus was baptized in a river (the closest parallel seems to be Osiris’ dismembered body being cast into a river and later recovered) by “Anup the baptizer” (Anubis, the embalmer god, was not called “the baptizer”), who was later beheaded (he wasn’t); Horus had 12 disciples (accounts mention four follower demigods as well as 16 human followers; there does not seem to be 12 of anything connected with Horus); that he raised Osiris, whose name is equivalent to Lazarus (he didn’t, and it isn’t); that Horus was crucified and resurrected on the third day (crucifixion was a Roman practice, and bodily resurrection a Hebrew belief, not known in ancient Egypt; claims of Horus’ death and rebirth seem to be borrowed from other Egyptian gods; there seems to be no relevant mention of a “third day”).

Elsewhere, Maher claims that 16% of the American population has no religious belief — “a huge minority,” he notes, compared to blacks (about 12%) or Jews (2.5%).

In fact, 16% of the population has no religious affiliation — not no religious belief — according to the massive recent study by the Pew Forum on Religion and Public Life. On the contrary, Americans are nearly unanimous (92%) in saying they believe in God. Only about 4% of Americans self-identify as atheist or agnostic.

Wait — it gets better. According to the study, more than half of self-identified “agnostics” and more than a fifth of “atheists” say that they believe in God or a universal spirit. “Atheists” and “agnostics” in double digits also believe in heaven and hell, pray at least weekly, believe that abortion should be illegal in most cases — and believe that “values are threatened by Hollywood.”

In one sense, Maher doesn’t present a straw man, inasmuch as the beliefs he lampoons are really held by real people, and in some cases, are fairly mainstream. Yet, Maher paints all religious faith with the same brush; he doesn’t want to hear about other interpretations of Genesis, since he’s convinced that the literal interpretation is the only one that matters.

Maher speaks briefly to a couple of educated and nuanced believers, including former Vatican astronomer Father George Coyne and Evangelical geneticist Francis Collins. Neither comes off badly, so Maher spends as little time with them as possible.

Tellingly, Collins is only allowed to address the subject of the historicity of the Gospels, a subject outside his area of expertise. If Maher ventured to put that question to an N.T. Wright, a Ben Witherington, a Father Mitch Pacwa or a Ronald Tacelli, the resulting footage would certainly have wound up on the cutting-room floor.

Steven G. Greydanus is editor

and chief critic at DecentFilms.com.

Content advisory: An American Carol contains much slapstick violence, including brief comic gore and recurring crass language. Might be okay for teens. Religulous contains fleeting explicit sexual content with partial female nudity and occasional obscene and profane language. Intended for mature audiences.