Fox News host Bill O'Reilly is less than impressed with the way Christian religious leaders in America are dealing with the "war on Christianity" being waged within the United States, and he is making no bones about telling the world why.

In his show, The O'Reilly Factor, the host cited a recent survey which found that 54 per cent of respondents feel like their religious freedoms are being threatened in the US.

He said that even the common man understood the implication of recent challenges to the faith and although Americans who stand up to gay marriage and abortion are being vilified in the media, leaders are still not being bolstered into action. 

O' Reilly expressed frustration over the lack of unified action among religious leaders to defend the tenets of the Christian faith, which have received strong blows amid growing support for same sex marriage and ongoing debates about the religious freedom restoration act.

"It is very rare to see any high ranking Catholic cleric defending the faithful publicly. Protestants are a little bit better, but organised efforts to defend the Christian faith are rare. Therefore, the anti-religion people have a free fire zone to attack at will."

He continued: "There isn't an organised attempt as there is in the gay lobby, abortion women's reproductive rights lobby. You don't have anything on the Christian side." 

Conservative commentator Ann Coulter, who was invited to discuss the topic on the show, was even more blunt in her assessment, calling the lack of unified representation for the faith an act of cowardice.

In a report by CBS News, Coulter said that in the face of challenges to the Christian faith, religious leaders have chosen to bask in image building exercises, rather than face up to their critics and actively fight for the position of the Church on key issues.

"The fact that these Christians would rather get praise from the 'New York Times' and Nicholas Kristof by changing bedpans of Ebola patients in Nigeria, rather than stand up to the 'New York Times' and fight against abortion, fight against these bullies... where are the Christians? And where are the Republicans?" Coulter said.

Coulter lamented that aside from individual Christian leaders occasionally speaking up and giving their opinions, none are truly representative of the faith as a whole.

"Most people would rather risk getting Ebola than being called a homophobe, a racist, the horrible accusations and ad hominem attacks thrown at Christians in this country," she said.