Comes from Seth McBee: Church isn't what you do on Sunday, or a building you go to
It is amazing how much you have to keep saying this. It is amazing how much you have to remind people who claim to follow Jesus that the church isn't an organization, but a people. I have once again been emailed by someone saying that I am spiritually confused because I allowed Muslims to come and pray in our church. Huh? If you actually broke that down, that would mean that I allowed a Muslim to enter into my body and pray inside of me. The term "church" literally means, a gathering of citizens called out from their homes into some public place, an assembly.
I understand where he is coming from. We say this over and over and everyone apparently seems to agree but in practice we still act like church is the self-sustaining institution where we meet instead of the living Body of Christ acting as His witnesses to a lost world.