For a Church to fulfill Jesus’s Great Commission, it must reach out to a lost world with the Gospel message. Then, it must take the people who respond to that message on the journey of faith, which is called discipleship.
For that person to become a fully devoted follower of Jesus, someone or several people must intentionally nurture that new faith until the person attempts to fulfill everything that Christ commanded.
How this plays out in the life of a Church is multifaceted.
Spiritual maturity is never achieved through one method. Numerous factors at play help each new believer become like Jesus.
There needs to be practical teaching of the Bible from others, along with the development of personal habits to water the seeds of faith further. Connecting with one or two other believers in authentic and open relationships is essential for the development of faith. Finally, serving others will help us grow as we place ourselves in situations that will stretch our faith.
The point is this: no ONE thing grows a person into a mature disciple.
This is why I encourage people to do multiple things when they join the Church I lead. I want people to be in worship every week, serve regularly, connect to others in a small group, and get into a 2-3 person discipleship relationship. I teach this because I know God will use one or all of those to help someone become a complete Christian.
At my Church, we are trying to develop a plan to help everyone grow, but you really never know what God is going to use. I do not recommend you throw all your eggs in one basket and hope for maturity. The best thing for someone who wants to follow Jesus is to open yourself up to a few growth opportunities and know that God will use those to transform you to be more like Christ.