Talk radio host Mark Levin invited Glenn onto his show Monday evening to discuss something ISIS is extremely open about, which has been largely disregarded by the mainstream media - Islam.
The infamous terrorist group has been completely forthright in claiming Islam both justifies and inspires their actions, from slaughtering Christians and selling minorities as sex slaves to taking over cities and establishing a caliphate controlled by Sharia Law. Why is the common denominator being ignored?
"We have to start calling evil by it's name," Glenn said.
Playing devil's advocate, Levin asked Glenn how he could dispute Islam is a "religion of peace."
"If you're living it as a religion of peace, you're a reformer," Glenn said. "The ones who are really truly the most Islamic are with ISIS and Al-Qaeda. They are living it to the letter, and they are living Sharia Law."
Glenn went on to say there are essentially two different kinds of groups within Islam. The reformers and the Islamists. And the number of Islamists in the United States is surprisingly high.
"52% say it is justified to have a violent overthrow of the U.S. government to replace the Constitution with Sharia Law," Glenn said.
Levin pointed out Glenn might be putting his life in jeopardy for writing his newest book, It Is About Islam.
"It is a very brave book that you've written. Very, very brave," Levin said.
Explaining the content of the book was not his opinion, but came right from the Koran and other Islamic writings, Glenn responded by saying he wasn't sure if it was brave or stupid, but it's important.
"I decided a few years back, I'm willing to die for the truth and what I really believe," Glenn said.
Listen to the full interview below.
Featured Image: Conservative radio host Mark Levin speaks at a "Cut Spending Now" rally at the conservative Americans for Prosperity (AFP) "Defending the American Dream Summit" in Washington on November 5, 2011. AFP PHOTO/Nicholas KAMM (Photo credit should read NICHOLAS KAMM/AFP/Getty Images)