The truth is hard to handle about Ricky Gervais’ The Invention of Lying: What could, and should, have been his Groundhog Day or Defending Your Life traffics in treacle that treads close to Bruce and Evan Almighty territory — biblical hair, beard and all.

Harold Ramis’s and Albert Brooks’s what-if comedies from the 1990s remain the modern pinnacles of the genre. Those savage send-ups of existence and death are simultaneously philosophical, existentially aware and sweetly romantic.

In disrupting a fantasy world where no one can tell a lie, Gervais and freshman co-writer / co-director Matthew Robinson can be admired for their audacity. Few would fire off heat-seeking missiles of religious satire in a romantic comedy, which leads to a few sublime scenes. However, as its tiresome, rickety resolution unfolds, Lying feels like it might have worked better as a one-hour special on Gervais’ native BBC.

Granted, Lying rebounds from the awful slog it seems it will be during the opening credits, with Gervais narrating seemingly as himself and explaining the conceit.

Deceit, flattery and fiction don’t exist in this fictional world where everyone is incapable of lying. “Lying” isn’t even a word, nor is “truth.” There is what is and there’s what isn’t. (Lying plays a bit fast and loose with the concept at times, creating some contradictions of motivation and history.)

Advertisements are dry and overt, sucking the hyperbolic artillery out of the cola wars. Marriage is based on good genes and fickle tastes. And summer blockbusters consist of Christopher Guest reciting dry facts of Napoleon’s campaigns.

Throughout history, everyone has called it as they see it — brutally, shallowly and straightforwardly. While it might seem like universal truth could be a social equalizer, it only enables misery, laziness and lack of fulfillment and emphasizes disappointment, insecurities and fears.

Case in point: Mark Bellison (Gervais), a chubby, lonely screenwriter at Lecture Films. (The only film studio, Lecture’s only offerings are oral-history recollections.)

Mark’s been saddled with the 14th century — not exciting or uplifting, what with the Black Plague and all — while he’s belittled daily by his secretary (Tina Fey) and writing rival (Rob Lowe).

He’s also romantically struck out yet again after a date with Anna (Jennifer Garner), who forthrightly believes he’s a bad genetic match for kids she’s desperate to have.

When fired by his ninny boss (Jeffrey Tambor) and threatened with eviction, Mark somehow lies to a bank teller and gets $800 instead of the $300 he actually has. No one has any reason to question him in a world where every utterance must be true.

From there, Lying unfolds like Groundhog Day in reverse. Mark learns from emotionally revelatory moments where he finds that lies can bring generosity and promise before he embarks on self-serving behavior to get money, glory and fame.

These sequences kill what little comic momentum Lying has mustered by then, and are filled with assaultive schmaltzy music by the appropriately named Tim Atack.

Last year’s far-superior Ghost Town let Gervais clasp his acidic edge as long as possible amid its romance and life lessons, and it’s disheartening to see this champion of cringe-comedy so earnestly squidgy. Not helping is an insanely stiff turn from Garner, who comes off as an alien encountering human behavior for the first time. It’s easily the worst-ever performance from this charismatic actress.

Lying rouses to life when it tackles death, with an inspired introduction of the “lie” of religion into a society convinced that only emptiness follows death. After comforting someone close to him about to pass on, Mark is sought out for all he knows about the afterlife.

In one of the year’s funniest scenes, Mark details the commandments of a peaceful afterlife (jotted on makeshift pizza-box tablets) for a crowd massed on his lawn. Perfectly edited by Chris Gill, it’s a dizzyingly uncomfortable, and uproarious, sequence in which humanity hangs on every word Mark says.

Too often lost in the resultant shuffle is what could have been a crystal-clear romantic angle: Of what worth is individual romantic willpower toward a man who claims he has every truth? Maybe Lying is like Groundhog Day: It feels like you’re reliving the same lame scenes over and over, powerless to change what happens in this profoundly disappointing comedy.