“And I did not see a temple in it, for Jehovah God the Almighty is its temple, also the Lamb is.

Revelation 21:22,

In truth, there is no need to construct a literal temple here. The ancient Jewish temple was just a pattern, and the reality of that pattern, the great spiritual temple, has existed since Jehovah anointed Jesus as High Priest in 29 C.E. (Matthew 3:16, 17; Hebrews 9:11, 12, 23, 24) A temple also presupposes a priestly class offering sacrifices to Jehovah on behalf of the people. But all those who are part of New Jerusalem are priests. (Revelation 20:6) And the great sacrifice, Jesus’ perfect human life, has been offered once for all time. (Hebrews 9:27, 28) Moreover, Jehovah is personally accessible to everyone living in the city.