
Very easily. Show them pictures of crime scenes perpetrated by Christian
terrorists in this country, if that doesn't convince them have them talk
to the victims of Christian terrorism. 

A brutal act of terrorism inspired by Christian propoganda was recently
commited on your very campus. 

Its very simple religious extremists of all religions put no value on
human life. Christian and Islamic fundamentalists put advancing there
religion above all else, even if doing so violates the religion itself.

P.S. I'm not saying all Christians are terrorists, I'm using "Christian
     terrorist" in the same way the media uses Islamic terrorist.