Someone has well said, "The Christian in the world is like a ship in the ocean. The ship is safe in the ocean so long as the ocean is not in the ship." One of the great difficulties with Christianity today is that it has admitted the strangers, the "people of the land," and recognized them as Christians. It does injury, not only to the Christians, by lowering their standards (for the average will be considered the standard), but it also injures the "strangers," by causing many of them to believe themselves thoroughly safe and needing no conversion, because they are outwardly respectable, and perhaps frequently attendants at public worship.
God's people are a holy nation, severed from all others unto God's service. Their faith, spirit, hopes and aims differ from those of the natural man. So dissimilar are these two classes that the attempt to fellowship one another would prove painful and disastrous. Especially would God's people be disadvantaged by such association. For the welfare of both classes separation from each other is necessary. Hence the exhortation, "Come out of her, my people." And when this separation is made, the faithful enter into closer fellowship with the Lord and with one another.
Num. 16:21, 26; Ezra 6:21; Prov. 9:6; Isa. 48:20; 52:11; Jer. 51:9; Acts 2:40; 2 Cor. 6:17—7:1; Rev. 18:4; 1 Cor. 6:11; Eph. 5:25-27; 1 Thes. 4:3, 4; 2 Tim 2:21; 2 Pet. 1:4.