1 Cor 10:2-4
all were baptized into Moses in the cloud and in the sea, all ate the same spiritual food, and all drank the same spiritual drink, for they drank of the spiritual Rock that followed them, and that rock was Christ.
The nation of Israel had 12 tribes. The spiritual nation of Israel has 7 as represented by the 7 lampstands before the throne of God(Rev1:20)
All of spiritual Israel will be contained within these 7 churches. It is my understanding that individuals can move from one to the other throughout their sojourn.
For example: an individual can go from toleration of Jezebel(2:20) to not bearing evil(2:2)
an individual can go from lukewarm(3:16) to abounding in riches(2:9)
an individual can go from NOT knowing or owning the saving gospel of Jesus Christ and the baptisim of the H.S.(doctrine)2:24) also see Acts19:2 to holding fast and not denying(2:13)
I have been given to understand that the works of the WBTS mirror, to an unmistakeable degree, the works of the church of Thyatira.