Yes I believe you are getting the point...your will...volition. If you recall in myths and fairy tales about vampires, if one did not invite the vampire in the vampire could not come in. I knew of someone who prayed that an angelic barrier of protection be established around his home even with specific boundaries established even as pertains to the front door. Those who could enter his home would remark things like: "I've never felt such a strong sense of peace."...inviting...
Anyways, it was made known to me that someone steep in the dark occult came by to pay a visit. The one visited is the type to never verbally invite anyone in his house. As the matter came known to me, he simply opened the door with the screen door left unlocked. While others he knew could walk in, the one that paid him a visit could not cross the barrier at all as the matter was made known to me--he was stopped right up to the line--toes on the line. The barrier was established to block out spirits of an evil or sinister or adverse kind. Thusly even if he were to open the door, he doesn't make any verbal invitation --let's God do the sorting.
"Do you mind if I come in?" Never answered with a yes--do you really know what they mean by "come in"?
Didn't quite go like this but...for perspectives:
In the State of Missouri [Marc Perkel found this out the hard way AFAIK], opening a door is taken as an invitation to police to enter. If your back yard lacks a fence, they take it as an invitation--thus they feel they can tow cars without a warrant if there isn't a fence. Ah and so there is this thing called "a close".
Lockable glass or screen doors in addition to a regular front or back door are handy for obvious reasons.