Basically, I oppose it on fundamental, spiritual reasons.
It is loaded with a flawed theological premise* and advocates holy war for all the wrong reasons. Ouch.
Of course, I'm biased and I am in no way saying that anyone that plays it is a bad Christian.
I'm just saying that if LB:EF is the Christian representative to the Gaming culture, we're in sad sad state.
*Edit: the flaw has nothing to do with Millenialism (Pre, Post, or A) or the Rapture. It has to do with Christian Jihadism, and loving your neighbors.