The question in the New Jersey case you refer to is not whether a church has to allow or perform gay weddings, the question is whether property owned by a Methodist-affiliated organization was in fact commercial property or religious property. The beach-side pavilion that the gays wanted to marry in was rented out for profit for concerts, performances, as well as weddings. The court has been asked to decide whether this was a commercial premises, in which case the state’s anti-discrimination laws apply, or whether it is a religious premises, in which case the church is free to allow or disallow whatever they want. As well, there appears to be some evidence that the organization voluntarily ceded the property (or part of it) to county in 1908 for use as public land, thus avoiding taxation. If it’s public land, then, again, the state’s non-discrimination laws apply. As far as I can find out, the trial hasn’t happened yet.
So it’s not as simple as you seem to imply in your post.
That’s my understanding also. The location in question was not a church sanctuary, it was a public place used for a variety of purposes ovr the years.