This is from the blog White Raiment:
“If you are a called one, then you are a called out one. If God has called you at all then he has called you to live in spirit outside the world system. Originally we were in that Satanic system with no way of escape; but we were called, and that calling brought us out. True, that statement is a negative one, but there is a positive side also to our constitution; for as the people of God we have two titles, each of them significant according to the way we view ourselves: If we look back at our past history we are ekklesia, the Church; but if we look to our present life in God we are the Body of Christ, the expression on earth of him who is in heaven. From the standpoint of God’s choice of us we are ‘out of’ the world; but from the standpoint of our new life we are not of the world at all, but from above. On the one hand we are a chosen people, called and delivered out of the world system. On the other we are a regenerate people, utterly unrelated to that system because by the Spirit we are born from above. So John sees the holy city coming down ‘out of heaven from God’ (Rev. 21:10). As the people of God, heaven is not only our destiny but our origin.
“This is an amazing thing, that in you and me there is an element that is essentially otherworldly. So otherworldly is it indeed that no matter how this world may progress, it can never advance one step in likeness to that. The life we have as God’s gift came from heaven and never was in the world at all. It has no correspondence with the world but is in perfect correspondence with heaven; and though we must mingle with the world daily, it will never let us settle down and feel at home there.”