The apostles of Jesus Christ built up the church in New Testament days. However, they were doing so anticipating the arrival of something more permanent very soon.
The letter to the Hebrews only counseled assembling together (that is, church) in view of preparing for the impending day of eternity (Hebrews 10:25).
The apostle Peter wrote about how to prepare for the impending eternal kingdom which would replace the temporal kingdom that was the church (2 Peter 1:11).
That eternal kingdom came, just as the Lord had promised.