Church as it is mentioned in the Bible, all of that in the new testament of it, is used with differences in meaning. But it never was meaning a building. There are any community of believers who generally are meeting together, with activities together as singing and praying, and being helpful for each others needs, which are a church. The first church, which had started in Jerusalem with the apostles being there, was showing a model for how church was to be, even without apostles there and if there were not the miracles. This would still include singing and praying, and with teaching from what they wrote which is in the new testament of the Bible, and being helpful for each others needs, which includes what believers do said in Acts 2:44-46, and again in Acts 5. There is elsewhere still the body of Christ which includes all the true believers yet in this world that is meant by the church.
Well all believers.. could be conceived as a body.. but that isn't how the bible defines the body of Christ. It's local in Matthew 16:18-- because it is local in Mathew 18: 18-20.
It is local in Ephesians, because the letter is to the church at Ephesus.. as an example to other churches plural. The 'general assembly' in Ephesians.. is either the Ephesus church or the future church in heaven.
It's local in Revelation.. with the seven churches as examples of churches overcoming issues in themselves.
It's local in Galations .. it being addressed to the churches of Galatia.
In Acts-- it's local initially with the church at Jerusalem.. and then with other church references.. such as Paul renting a synagogue for his church.
It's local in 1 and 2 Timothy.. as Timothy being encouraged by Paul as a pastor of a church.
There will be a time when all believers are actually one body.. but that isn't the case now. A church assembles. A body of Christ of all redeemed does not assemble.
All redeemed are obviously an entity themselves.. that is the Family of God. A family.. does not need to assemble to be a family.
From Arthur Pink in Churches of God:
"Now the kind of church which is emphasized in the N.T. is neither invisible nor universal; but instead, visible and local. The Greek word for “church” is ecclesia, and those who know anything of that language are agreed that the word signifies “An Assembly.” Now an “assembly” is a company of people who
actually assemble. If they never “assemble,” then it is a misuse of language to call them “an Assembly.” Therefore, as all of God’s people
never have yet assembled together, there is today no “universal Church” or “Assembly.” That “Church” is yet future; as yet it has no concrete or corporate existence."