I agree that getting permission from a church before hunting is a must. Churches are definitely not public property! They are private property and are owned by the members of the church. And if you do get permission, make darn sure that when you leave, you leave the property as close to the condition you found it as you possibly can!
There is an old church that is about a mile from my house. The building was built on the property around 1899 or 1900. But, they had services there for some time before the building was built. At first, I didn't know how old the church was, but could tell by looking at it and the dates on some of the headstones in the adjacent cemetery that it was probably a turn of the century church. I figured it to be prime TH ground! And, since it appeared that regularly scheduled services were no longer held there, I figured I could easily get permission to hunt.
It was somewhat of a lengthy process finding out who I needed to contact about the church. But, I did it. I learned that the treasurer for the church was a elderly lady who lives in a small town about 5 or 6 miles from me. When I called her and explained what I wanted, she told me that she would have to get in touch with the rest of the members and find out what the general consensus was. She promised to call me back when she had an answer.
About 4 weeks later, she called me back. She said that the general consensus of the members was that they didn't want anyone trespassing for any reason other than to visit the graves of family members buried in the cemetery. Here's why.... She said that a few years back a church member saw a man who was metal detecting on the church grounds. Thinking that no harm was being done, the member said nothing. A few days later, another member went to the church for something and was horrified at what he found. There were holes that had been dug all over the church yard. He said that the holes ranged in size from about 3 inches in diameter to over 12 inches in diameter... and none of them covered up!!
Since the property had already been hunted, I don't know what my chances would have been of finding anything of any value. But, thanks to the actions of one uncaring, ignorant,a$$hole, I was denied permission to hunt the property. And, I'm sure the same will hold true for any other would be THers for as long as there is one of the church members living!
Good luck,
Robert