From the outset, it is important to note that church membership did not begin in the New Testament, but rather in the Old Testament. Exodus 19 is considered the first church gathering in the Bible, because God commanded Moses to consecrate and assemble the people of God before his presence. And in Deuteronomy we read a description of the church gathering at Sinai, “The Lord came from Sinai…he came from the ten thousands of holy ones…yes, he loved his people, all his holy ones were in his hand” (Deut. 33:2-3). This passage captures an eschatological glimpse of future glory where heaven meets earth at Mount Sinai.
Exodus 19 presents an eternal reality of the dynamic of the visible and invisible church. Edmund Clowney defines it this way, “the church invisible is as God sees it, and the church visible is as we see it.” Church members only interact with the visible local church, and have no access to the invisible church, because God alone knows his elect ones. A profession of faith does not necessarily indicate a possession of faith. Those who are members of the invisible church will indeed be members of the visible church if they are not already, but membership in the visible church does not guarantee membership in the invisible church. Therefore, the redeemed and the unredeemed will remain in the visible church until Christ returns. Read more»
—Ekemini Uwan, “Church Membership: Who Needs It Anyway?”