The problem here is that we have allowed our thinking to be skewed to believe a separation can be made between the sacred and the secular. Our love for the doctrine of the separation of church and state has blinded us to the reality that all of life is ultimately about religion. But the person who declares unbelief is making a statement of faith as surely as the congregant who recites a creed in church. That the traditions do not agree does not mean they should be denied the opportunity to speak to society. Nor does it matter that some segments of society deny the importance of any tradition identified as religious.
Christians seem to be the worst about inflaming an argument.
Given the conservative understanding that they hold absolute truth, this hardly seems surprising. Few other religions are as confrontational with society as Christianity is, from the conservative crusade against abortion to the liberal concern for the poor. But it needs to realize that simply decrying sin will not affect much of the change it seeks. Christians could learn a lesson from their founder. What we know of Jesus from the New Testament shows a man who saved his harshest and most inflammatory comments for the leaders of his own religion.