Notice how the gathered are referred to by Christ as "my people" and "house of Israel" and "my Zion." When the gathering is complete, the various groups are no longer separately identified. On the other side of this gathering they will be "one" people and a restored "house of Israel."
Then they are "established" as "Zion."
If you want to have a place there, do your connections in a church, organization, fraternity, fellowship, quorum or brotherhood matter? If not, what association alone will allow you to participate? How important is the "testimony of Jesus?"