He lists seven problems, which you definitely need to read. I'll just highlight one:
6. The flag becomes a symbol like the cross.<idle musing>
I imagine that there may be as many American flags on the platforms of American churches as there are crosses. Indeed, there are probably a good many American churches that would be angry at the idea of having a cross because of some association of it with Catholic perversity.
He's right. There are more flags than crosses. I was at an event several years ago in a megachurch's building. They had no crosses in the building. But they had a huge—and I mean huge U.S. flag flying in the front. There was no way you could have told it was a church building; in fact, it looked more like a government building.
I asked about the absence of the cross. They said that they wanted to make the building available to all and that a cross would be a hindrance to that. Exactly! Isn't that what skandalon means?!
When I questioned the flag versus the cross, I was viewed as a heretic...I guess I am—if your religion is nationalism.
So, Ken, welcome to the club of heretics... : )