The church is the Body of Christ. Ephesians 1:22-23 says, "And He put all things in subjection under His feet, and gave Him as head over all things to the church, which is His body, the fullness of Him who fills all in all." The Body of Christ is made up of all believers from the time of Pentecost until the Rapture. The Body of Christ is comprised of two aspects:
(1) The universal church is the church that consists of all those who have a personal relationship with Jesus Christ. 1 Corinthians 12:13 says, "For by one Spirit we were all baptized into one body, whether Jews or Greeks, whether slaves or free, and we were all made to drink of one Spirit. For the body is not one member, but many." We see that anyone who believes is part of the body of Christ. The true church of God is not any particular church building or denomination. The universal church of God is all those who have received salvation through faith in Jesus Christ.
(2) The local church is described in Galatians 1:1-2, "Paul, an apostle…and all the brethren who are with me, to the churches of Galatia." Here we see that in the province of Galatia there were many churches - what we call a local church. A Baptist church, Lutheran church, Catholic church, etc. is not THE church, as in the universal church – but rather is a local church. The universal church is comprised of those who have trusted in Christ for salvation. These members of the universal church should seek fellowship and edification in a local church.