Joining a church used to be an act of conformity in our society. You joined a church because everybody else did. Now the rules have changed and conformity is no longer a motivating factor. In fact, George Gallup has found that the vast majority of Americans believe it is possible to be a "good Christian" without joining (or even attending) a local church.
Because of that, membership is now an act of commitment. The way we motivate people to join today is to show them the value-for-value benefits they will receive in return for their commitment. It has been found that when people understand the meaning and value of membership, they get excited about it.
There are numerous benefits to membership
I emphasize the fact that the church provides people with benefits they cannot find anywhere else in the world:
Why do churches have so many people on their membership rolls who give little or no evidence of Christian commitment or even conversion? Why do many churches find it difficult to motivate members to give, serve, pray, and share their faith? The answer is that the members were allowed to join with no expectations placed on them. So you get what you ask for.
Paul mentions two different types of commitment in 2 Corinthians 8:5 (GNB): "First they gave themselves to the Lord; and then, by God's will, they gave themselves to us as well." We call these the first-base commitments. You commit yourself to Christ for salvation and then you commit yourself to other Christians for membership in our church family. Thus, from this point we define koinonia (fellowship) as "being as committed to each other as we are to Jesus Christ.
Jesus said that our love for each other was to be the mark of discipleship (see John 13:34–35). I believe it's an indictment of Christianity that most believers can quote John 3:16, but they can't quote 1 John 3:16: "This is how we know what love is: Jesus Christ laid down his life for us. And we ought to lay down our lives for our brothers." Most churches are silent about developing that level of commitment to each other.
To develop that level of commitment to each other, we have four requirements for membership: (1) a personal profession of Christ as Lord and Savior, (2) baptism by immersion as a public symbol of one's faith, (3) completion of the membership class, and (4) a signed commitment to abide by James Chapel's membership covenant.