Jesus preached separation. Jesus told us to strive to avoid error. I don't know if Rush is saved, or not, but he does say he believes God created man in his own image, and he says he believes abortion is sin. He touts the biblical principle of personal financial responsibility, and he practices the biblical principle of giving to the needy, & the sick. His Marine Corps Law Enforcement Charities have spent literally millions of his dollars sending well-achieving poor kids to college for free, and he supports the Wounded Warriors charities. He gives his own money to people who've been robbed. He sends people who could not afford it to the Super Bowl, all expenses paid.
He also teaches against the homosexual influence, and is one of the people warning against the oncoming one-world government.
I like the separation he talks about. Seems to me some Christians want to be loved by the world more than they want to obey scripture. Some on this very board included.