How Come Christians Are The Only Religious Group Of People Who Take Their God's Name In Vain? No Other Religion Does This.

This is not necessarily true. It is not a term to be wholly associated with Christians. The name God does not just refer to the Christian God but can be used to call other God's such as, for example, the God of Judaism. So to say that it is a Christian term would be wrong and unfair. It is however agreeable that this is a western phrase, although majorly Christian the west does contain other religions. It does not hold the meaning of taking the Lords name in vein any longer and now is just a turn of phrase. I do hope this helps in your understanding and i wish you all the best!

Because, in general, the wealthier the western nations became, the less they needed to invoke God's name in their daily lives. Religious fervor tends to be more relevant and more evident in poorer countries rather than in rich countries like US, Europe and Japan. Of course, there are still those that don't fit into this pattern. But more and more it is a fact of life.