Very interesting and very edgy question. The mention of Church in the Bible is often referring to the multitudes of Christians and not just the building. I'm curious about the building in this question.
I know that these days most churches are designed to be seeker-friendly, in a way that their doors are "open" to all individuals during all hours, including service. What I'm curious about, is why some Christians believe that their church should not be opened to the non-believing population during service hours.
More specifically J.H. Skelly and his street preaching ministries believes that non-believers should not be allowed inside of the church during the service hours.
What is the Biblical basis for this kind of thinking?