There are many reasons why church-state separation is a big deal (indeed, the fact that a valid constitutional claim is being raised should, in itself, qualify the matter as a legitimate "big deal"), but there is a psychological component to such issues that sometimes gets overlooked amid all the legal analysis. This component, which I call "crisis-induced devotion" (or "CID"), illustrates why governmental religiosity, while sometimes appearing benign and unimportant, is always at least potentially dangerous.
MORE: http://www.psychologytoday.com/blog/our-humanity-naturally/201305/understanding-why-god-references-are-big-deal
