Jesus said "Go make disciples." This is the ultimate mission of the Church. If we fail at making disciples, it doesn't matter how many buildings we build, sermons we preach, or songs we sing; we will have failed at God's primarily calling to his people. We never want Jesus' last command to become our least concern.
Becoming a disciple isn't a linear process. You don't complete a series of classes or fill out a set of workbooks; it's a lifelong journey that looks different for each person. However, there are two things that are necessary for every disciple.
When we begin following Jesus, when we become a disciple, we identify with His death, burial, and resurrection in baptism. Baptism is a public declaration that we belong to the family of God.
That's what the Church is, God's family intent on living out his mission on earth. You can't be a go-it-alone follower of Jesus. To follow Him is to be a part of his family, to invest what God has given you into others and to allow others to invest in you, as we become more like Jesus together. That is the meaning of discipleship, and at NCC we facilitate discipleship through small groups.