Why is church membership important? The universal Church—the Body of Christ (Romans 12:5)—is composed of all true believers
in Christ. Nonbelievers aren’t part of the Body of Christ; therefore, it would seem that God keeps a “membership list” of who is in the Church. We see just such a list in Revelations 20:12, the
Lamb’s book of life. If the universal Church has a “membership roll” in heaven, it would be appropriate for local churches to maintain a list of members on earth.
“And the Lord added to them day by day those that were being saved” (Acts 2:47). This
verse indicates that salvation is a prerequisite for being “added” to the church. Churches today who require salvation before membership are simply following the Biblical model. See also 2
Membership in the local church is strongly implied in Paul’s instructions to the
Corinthians to “put away from among yourselves that wicked person” (1 Corinthians 5:13).
The preceding verse speaks of those “without” and “within” the local church. Such
language is meaningless without a clearly defined group of members.
Why is church membership important? Church membership is a way of officially
identifying yourself with a local body of believers. Church membership is a statement that you are in agreement with that universal church and are a representative of it.
"All Scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness:" II Timothy 3:16