Thanks for your interest in membership at City.
I wanted to briefly explain why we have membership at City. The clear teaching of scripture is that the local church is the context for living the Christian life. While the term "church membership" can't be found in the bible, the concept is all over the place. In fact, it would be difficult to obey almost any of the New Testament exhortations if we weren't part of a local church. All the NT epistles are written to churches or church leaders. In the apostolic church to be a Christian was to belong to a local church.
We see the priority of the church as we consider that Christ has died for the Church, his bride (Ephesians 5:25-27); and the necessity of the Church as the body of Christ (1 Corinthians 12:12-27). That is to say, we should never think of Jesus apart from His body and bride. We should never think of Jesus apart from His church.
The local church serves an embassy role in God’s kingdom, as it publicly recognises the members of the kingdom and declares the home nation’s interest in foreign lands.
The local church is where we serve and build others up with the gifts we have been given (1 Corinthians 12), and where we are held accountable to our profession of faith in Christ. It is here in the local church that God wants to bring people to faith in Jesus and conform them into the image of Jesus as they walk in a living relationship with Him and His people.