In other words, can you please explain why priests should not be forced to marry gay couples? "Force" is a loaded word, of course - I'm not necessarily talking about armed agents going into a church and demanding that a priest perform a marriage ceremony, but rather referring to the full range of coercive actions available to the federal government. For example, if a church refuses to perform same-sex marriages, why should they get tax-exempt status?
Maybe churches shouldn't have tax exempt status at all. Taxing some religious organizations and not others sounds unconstitutional though.
Because part of the whole point of a religion / creed is that you do some things and not others.
"Forcing priests" means no freedom of religion expression, one of the older democratic rights.