The word, "church": definitions.
Harper's Bible Dictionary:
ekklesia, "assembly of citizens called out".
What comes to mind when we think of the church? A building? A denomination? All Christian groups? Do we divide the church into Catholics, Protestants, Pentecostals, etc.?
It is a hazy idea at best. It is something we wonder about and even worry about at times, but then relegate to the realm of mystery, hoping and praying that because we belong to a local church and are born again and doing the best we can to serve Him, we are members of Christ's body -- that knowing and quoting the relevant scriptures makes it so.
Are there two expressions of the reality of the church? The CHURCH and the church? Is one in heaven the other on earth? Is one mystical (invisible) and one local and visible with a street address and zip code? And if so, who belongs and who doesn't? If we are members of a visible church are we automatically members of the invisible church, members of the Body of Christ? And how if ever do the invisible and visible meet -- what is the eternal connection?
Scripture tells us that the church is the Body of Christ. And the Body of Christ is a spiritual house, being built up as a dwelling for God in the Spirit. It is the true tabernacle which the Lord pitched not man, that is to say, not of this creation. Its foundation is the apostles and the prophets, Christ Jesus Himself the cornerstone.
And wonder of wonders, Scripture also says that we, too, can be part of this marvelous temple, this sanctuary, the true tabernacle -- if we allow ourselves to be built up in Christ Jesus. But how are we built up in Jesus Christ; how do we become members of His Body? As I write this, I am aware that my mind is loaded with mistaken beliefs and ideas. The first step for me is to be untaught, I need to "un-learn".