The edifices they have built, are certainly crumbling. They have hijacked all the covenants, which is nonsensical. I have always maintained, one cannot be the figurative tribes of Israel and be governing the tribes of Israel. You are either the one or the other (Rev. 7:1-8). The leadership of Israel will fall under the kingdom covenant (Matt. 19:28; Luke 22:28-30).
Who is the Israel of God (Gal. 6:15, 16)? According to Rom. 11 Paul explained it with an olive tree. All Israel (olive tree) = Jewish remnant (natural branches) + Christians (wild olive branches): Rom. 9:27; 11:16, 17, 25-27.
The new covenant is concluded with "all Israel," which will be permanent, as indicated above (Hebr. 8:10; 13:20). It is the former covenant that will become obsolete (8:13).
So, who makes up the temple?
16 Do YOU not know that YOU people are God's temple, and that the spirit of God dwells in YOU?
17 If anyone destroys the temple of God, God will destroy him; for the temple of God is holy, which [temple] YOU people are. (1 Cor. 3:16-17; cf. 1 Cor. 6:16; Eph. 2:21, 22).
JWs insist the 144,000 make up this temple. The bad news for them is that there is no temple in heaven (Rev. 21:22). Where Revelation mentions the heavenly sanctuary, this is the tabernacle sanctuary (cf. Rev. 15:5). Another indication that the temple is on earth. The courtyard of this temple will be trampled by the nations for 42 months (Rev. 11:2).