Here’s an excellent post explaining the problems of the World Trade Center Girder Cross, why there is a lawsuit to stop it, and why you should be opposed to this monument even if you’re Christian. The first paragraph is a quote from President James Madison that is so perfectly apt even to this day that I will post it in its entirety here in addition to a link to the rest of the explanation about this cross in particular.
It is proper to take alarm at the first experiment on our liberties. We hold this prudent jealousy to be the first duty of Citizens, and one of the noblest characteristics of the late Revolution. The free men of America did not wait till usurped power had strengthened itself by exercise, and entangled the question in precedents. They saw all the consequences in the principle, and they avoided the consequences by denying the principle. We revere this lesson too much soon to forget it. Who does not see that the same authority which can establish Christianity, in exclusion of all other Religions, may establish with the same ease any particular sect of Christians, in exclusion of all other Sects? that the same authority which can force a citizen to contribute three pence only of his property for the support of any one establishment, may force him to conform to any other establishment in all cases whatsoever?
– President James Madison, Memorial and Remonstrance Against Religious Assessments (1785)
This quote alone should explain why the cross is unconstitutional and why it should be opposed even by Christians. Remember, as Madison points out, if one sect of Christianity is established, all others will suffer. And, given the great many sects of Christianity, the likelihood that your particular flavor (if you are Christian) will be selected is very small. And, the differences in the sects can be significant. Some engage in ritual mock cannibalism; some do not. Some worship graven images; some do not. One notable flavor of Christianity is opposed to using the cross as the symbol of Christianity because it is the murder weapon of Christ. They’re right too, on that subject at least. Some flavors of Christianity do not allow medical care of any kind. Some do not allow abortion or contraception. Some are fine with both. Some churches are even fine with homosexuality.
On most of these issues, if you are a Christian, you likely have a strong opinion. What if your sect is not chosen as The One?
This is why even Christians should oppose this obvious endorsement of Christianity as the national religion in our once-secular nation. For any non-Christians, the reasons should be blatantly obvious.
Anyway, here’s the link to a far better post than mine. You won’t burn in hell just for reading it.