Paul said the reason he wrote the first letter to Timothy was “that you may know how to conduct yourself in the house of God, which is the church of the living God, the pillar and the ground of the truth.” (1 Tim. 3:15) This says to me, even at first glance, that Timothy was in the church, along with all others who had been bought with the precious blood of Jesus (Acts 20:28). I think you could assume from Paul’s letters, also, that he knew of no “unchurched Christians.” That term would have been meaningless to him, an oxymoron. Why would a Christian separate himself from the church of the living God which is the pillar and the ground of truth? The second thing that jumps off the page at me is that this is the church of the living God where those who are living because of God’s grace gather. It is not a net to catch seekers but a house for the godly, that there by the truth of God’s Word they can be built up and sent out to “do the work of the ministry” (Eph. 4:11-13) and preach to the seekers!
Are you a member in good standing in the pillar and the ground of truth?