Sitting in a pew at Cornerstone Family Church in Des Moines, Huckabee was merely a parishioner, a man being ministered to on the eve of perhaps the most important week of his life. The pastor’s sermon could not have been more fitting. Titled “Pressing Toward the Mark,” it was a Biblical message about perseverance in the race of life. “Have you ever felt like giving up? Of course you have!” the pastor, Dan Barry, intoned. “That’s why you’ve got to press on … Stay in the game!”

The sermon applied to the other race Huckabee’s running, as well. The GOP upstart, who told reporters after the service that he had prayed for “strength for the week,” has endured a thrashing in recent days—over his foreign policy pronouncements and his record back in Arkansas.

He’s given his critics some choice openings. Speaking after the assassination of former Pakistani prime minister Benazir Bhutto last week, Huckabee strangely tried to link the story to the threat of illegal immigration, a huge issue among Republican voters in Iowa. Meanwhile, Mitt Romney and other opponents have been running attack ads around the clock on Iowa’s TV and radio stations, trashing Huckabee’s record on pardons and taxes—charges that Huckabee’s campaign, still limping financially and lacking a strong organization, has been largely unequipped to answer.

If the polls are to be believed, the negative advertising is having an effect. According to the latest MSNBC/McClatchy/Mason-Dixon poll out last weekend, Huckabee’s numbers in Iowa are slipping. According to the survey, Romney now leads Huckabee 27 percent to 23 percent in the state—though that lead remains within the survey’s 5 percent margin of error. Compare that to the state of play just three weeks ago, when Huckabee led Romney 30 percent to 20 percent. One of the key factors in Huckabee’s slip: his edge over Romney among self-described born-again Christians has dropped from 23 percent to 1 percent.

If he’s worried about the new numbers, Huckabee isn’t showing it. While Romney, Fred Thompson and all the Democratic presidential hopefuls spent much of the day Sunday crisscrossing the state wooing voters, Huckabee had no public events, aside from the impromptu church visit and a sit-down on “Meet the Press.” His tentative public schedule for the week, released late Sunday night, is just as leisurely. On Monday he’s scheduled to hold a news conference and celebrate New Year’s Eve with supporters, but the rest of the events are photo-ops, including a haircut and a run at a local park. On Wednesday, the day before Iowans vote, he’s scheduled to appear at just two town halls in the state before traveling to California to appear on “The Tonight Show With Jay Leno.”

But Huckabee does seem to be fine-tuning his message a bit. Over the weekend the former governor, who had previously vowed to end the campaign on a positive note, unveiled a much tougher stump speech to push back against Romney and the Club for Growth, which is spending millions on TV ads attacking Huckabee’s record of raising taxes in Arkansas. Huckabee, who until recently referred to Romney in speeches as “one of my rivals,” attacked the former Massachusetts governor by name and accused him of running ads that are “desperate and frankly dishonest.”

“If a person is dishonest in his approach to get the job, do you believe he will be honest in telling you the truth when he does get the job?” Huckabee said during a meet-and-greet at a restaurant in Indianola. “You need a president who gets the job honestly. Because if they don’t get it honestly he probably won’t serve honestly.”

It’s unclear if Huckabee’s tough talk will be enough to keep his Iowa dream alive come Thursday. But for now, at least, he’s keeping the faith. At Cornerstone on Sunday morning, the former governor listened as Barry preached the virtues of sticking it out in the face of adversity. “You’ve got to do anything you can to stay in the race, and get your game back on,” Barry passionately declared. The preacher was talking about facing down the devil. But the message had resonance beyond the church walls, back out on the trail.