To be a disciple of Christ means I am not a Christian based on "denomination", but rather, I am a Christian simply because I have accept Christ as my Lord and Savior. As a disciple, my Christian faith should be inward, not outward because the Bible teaches that faith is of the spirit and not of the flesh. Christ dwells in my heart, and "Christ in you, the hope of glory" (Colossians 1:27) is the burning core of the Christian faith.
In the Bible talks about two kinds of church memberships. First Kind of Member is at SALVATION: At the instant of our conversion, we become "eternal life members" in the universal church of Jesus Christ, based solely on His merit and grace. If you are a Christ-follower, then you are already this kind of member. This is eternal and unchanging (I Corinthians 12:12-13; Ephesians 2:13-22; 4:3-6; Colossians 1:13-22). Everyone who is saved is a member of God's Kingdom.
Second Kind of Membership is at Local Church, the Bible also assumes those "positional members" physically in a visible local Church and become deeply involved in the participation of a local assembly (Romans 12:1-8; 1 Corinthians. 12:25-31; 14:12, 26; Hebrews 10:24-25; I Tim. 3:14-15). We belong to a local Church because God told us through the Word (Romans 12:1-8; 1 Corinthians. 12:25-31; 14:12, 26; Hebrews 10:24-25; I Tim. 3:14-15). The primary reason to become a participating member is not to gain a personal advantage, but to identify with the characteristics of biblical maturity and commitment to the mission and future of a local church. The Scriptures teach every believers to be committed to a local church where he or she is loved and cared for, instructed in the things Christ commanded, encouraged to grow spiritually, and serving Christ effectively. If we serve effectively, a local church can and WILL grow. We are to grow spiritually and allow the Holy Spirit do the rest including church growth.