Franklin Graham has hit back at atheist groups, who he says are bullying Christians into silence. His comments come following calls by the Military Religious Freedom Foundation demanding an Air Force general be court-martialed for crediting God at a National Day of Prayer event.

Graham posted on his Facebook account this week: "Are Christians the only group of people who cannot identify themselves publicly in this country? Are we the only voices who cannot speak?"

He added, "I guess this group would've tried to court martial George Washington when he prayed at Valley Forge! Come on —whose civil liberties are really being infringed on here? They want to bully Christians into silence."

Major General Craig Olson, the program executive officer for C3I and Networks at Hanscom Air Force Base, was targeted by the Military Religious Freedom Foundation, which called for him to be "brought to justice for his unforgivable crimes and transgressions."

The "unforgivable crimes and transgressions" the MRFF was referring to were when Olson credited God for the success in his career while speaking at a National Day of Prayer Task Force event on May 7.

Olson said at the event: "He put me in charge of failing programs worth billions of dollars. I have no ability to do that, no training to do that. God did that. He sent me to Iraq to negotiate foreign military sales deals through an Arabic interpreter. I have no ability to do that. I was not trained to do that. God did all of that."

He also made call to prayer for the leadership of the Defense Department, saying they needed "to humbly depend on Christ," and a prayer for troops getting ready to be deployed so that they could endure by "depending on Christ."

In response, Mikey Weinstein, the MRFF head, sent a letter to the Chief of Staff Gen. Mark Welsh. He wrote: "Olson's highly publicized, sectarian speech is nothing less than a brutal disgrace to the very uniform he was wearing and the solemn oath he took to support and defend the United States Constitution."

He added, "This public address was his, and the USAF's, 'contribution' to this scathingly sectarian 2015 version of the [task force's] annual shame spectacle and display of Christian supremacy and exceptionalism held in the Cannon House Office Building on Capitol Hill."