With nearly 200 retired generals and admirals from all branches of the US military coming together to voice their opinion against the Obama administration's nuclear deal with Iran, top US government officials have got to pay full attention, Reverend Franklin Graham said.

"I think Congress had better listen," he wrote on his Facebook page as he recounted how the group of retired military leaders sent a letter to lawmakers, urging them to reject the Iran nuclear agreement.

"They made it clear that this [nuclear deal] threatens national security—and these men know! Retired Air Force Lt. Gen. Thomas McInerney, who was vice commander of US Air Forces in Europe, said he considers the agreement the most dangerous nuclear accord in US history," said Graham.

He quoted McInerney as saying, "The number one leading radical Islamic group in the world is the Iranians. They are purveyors of radical Islam throughout the region and throughout the world. And we are going to enable them to get nuclear weapons. Why would we do that?"

Graham said McInerney posed a riveting question, something that President Obama and the US Congress must seriously consider.

The voting would take place on Sept. 17, and Graham hopes that people in charge would be moved by wisdom and God's guidance.

"Let's pray that Congress will have the wisdom to stand up and vote against this dangerous proposal. If you're as concerned as I am, let your representative in Congress know today that they should vote no to the Iran nuclear deal," he said.

Graham also expressed disgust that America, which is supposed to be a Christian nation, is expressing partiality towards Muslims. One indication of this, he said, is that Orlando International Airport is spending $250,000 to build a prayer room for Muslims.

"The airport already had an interfaith prayer room since 1983 (with prayer rugs available in it)—but that wasn't enough. How loud do you think the objections would be today if they spent $250,000 in taxpayer money to build a new prayer room exclusively for evangelical Christians? Or for Jews or Mormons or any other group?" he asked.