Church membership is a biblical privilege and responsibility. In 1 Corinthians 12:12, the Bible says “For just as the body is one and has many members, and all the members of the body, though many, are one body, so it is with Christ.”
It is obvious from the New Testament that individual believers identified with God’s people, the church, and expressed their faith together as members of the body of Christ. Acts 2:37-47 records how the requirements for membership were salvation (regeneration by the Holy Spirit) and baptism as a confession of faith in the Lord Jesus Christ.