Please post the Biblical junction against this that would give the preachers and ministers the moral right to stick their nose in air on this. I can't recall it.
Let's say, for example, that two lesbians came to a conservative church and wanted the minister to perform a marriage ceremony. If the church is against gay marriage, the minister has every right to refuse to perform the service because the wedding would, in its execution, carry the implied endorsement of the church.
While that's an extreme example, I've known many churches that require counseling for prospective couples before they will agree to perform the ceremony because they believe that a marriage should follow the principles set forth in Scripture. If, in the minister's judgement, the couple seems too immature or has other issues that don't reflect a Christian lifestyle, they'll refuse to perform the service.
It doesn't mean the couple can't get married. It just means the couple can't get married *at that church*.
The JP is different. He's a civil servant. He has to marry any couple that meets the qualifications set forth by the state, not those that fit his own religious beliefs. See the difference? The minister is the official of a religion. The JP is the official of the state.