Church in the New Testament is understood in two ways: those who are believers and a local body ( i.e., the Church at Corinth). Church can also be used to refer to two categories: the visible and the invisible. The visible church consists of all the people that claim to be Christians and go to a church. The invisible church is the actual body of Christians--those who are truly saved.
The true church of God is not an organization on earth consisting of people and buildings but is really a supernatural entity comprised of those who are saved by Jesus. It spans the entire time of man's existence on earth as well as all people who are called into it. We become members of the church (body of Christ) by faith (Acts 2:41). We are edified by the Word (Eph. 4:15-16), disciplined by God (Matt. 18:15-17), unified in Christ (Gal. 3:28), and sanctified by the Spirit (Eph. 5:26-27).