"As an elected leader, I am all too aware of government's limitations when it comes to fixing things that are spiritual in nature," the Republican leader said in an online video advertising "The Response," a seven-hour mass rally.
"With the economy in trouble, communities in crisis, people adrift in a sea of moral relativism, we need God's help," said Perry, who has flirted publicly with seeking his party's nod to take on President Barack Obama in November 2012.
The gathering, held at a Houston stadium and broadcast online, could help burnish Perry's credentials among religious conservatives who shape Republican presidential primaries, but the blend of politics and piety could alienate swing voters thought to decide general US elections.
Public shows of religious faith are nothing new to US politics -- George W. Bush said during the 2000 campaign that his favourite philosopher was Jesus Christ -- but at least one of the groups backing the event could raise eyebrows.
The American Family Association, listed as a "hate group" by the Southern Poverty Law Centre that tracks US extremists, rails against "the homosexual agenda" and accuses Obama of having "shown far more interest in promoting Islam than his own self-proclaimed Christian faith."
But Barry Brummett, who studies the appeal of Evangelical religious discourse at the University of Texas at Austin, says Perry's public shows of faith are "not beyond what you might see a 'mainstream' political leader do anywhere."
"Now if he kept doing this, started seeing visions and handling snakes, then people might say he's gone over the top," Brummett told AFP.
James Henson, who directs the Texas Politics project at the University of Texas at Austin, said Perry is right to focus on religious conservatives, a potent force in early Republican contests.
His "appeal to Evangelicals, which is what 'The Response' is, helps him in the primary or they wouldn't be doing it," said Henson, who noted Perry "hasn't hesitate" to use such appeals "for political reasons."
Perry may take a hit if the event falls flat. Just 8,000 people have registered to attend the rally in a stadium that seats 71,500 people.
Though all governors and many other political leaders received an invitation, only Kansas Governor Sam Brownback answered with a tentative yes.
Organizers, however, are predicting success and note that 1,100 churches in the United States and "prayer partners" in Indonesia, India and Brazil "will also take to their knees" while watching a live stream of the event.
"There are a lot of ordinary men and women of faith attending, and few with public titles," Eric Bearse, a spokesman for the Response, told AFP.
"There will be a number of notable leaders in the spiritual committee leading the assembly from the front stage."
Two of Perry's rivals face balancing acts of their own when it comes to religion: Former governors Mitt Romney of Massachusetts, the Republican frontrunner, and Jon Huntsman of Utah are Mormons.
Some Republicans fret that Evangelical Christian voters will not support a Mormon candidate, though others counter that a sour economy and fierce opposition to Obama will rally the party in 15 months.
Perry's Texas roots could be a double-edged sword, with some voters suffering from "Texas fatigue" after eight years of Bush, and others eager to embrace a southerner.
"The South is the largest region in the US and the most Republican," John Fortier, director of the Bipartisan Policy Centre’s Democracy Project, wrote in an e-mail. "There is no other credible southerner in the race."
Republican Representative Michele Bachmann, a darling of the "Tea Party" movement, hails from Minnesota and has mounted an aggressive campaign in Iowa, home to the first-in-the-nation Republican presidential caucus.
The November 2012 is expected to turn on Obama's handling of the economy, and Perry could be expected to trumpet the robust job growth of the "Texas Miracle" he has overseen since taking office in 2000.
But critics of Perry point out that his state has high rates of poverty, and he would likely face fire over telling an anti-tax "Tea Party" rally in April 2009 that Texas might be better off seceding from United States.
Either way, Perry "has made a series of concerted efforts to rebrand Texas -- it's no longer Bush's Texas but Perry's Texas," said Henson.
Copyright AFP (Agence France-Presse), 2011