“And He said to them, “Follow Me, and I will make you fishers of men.”” (Matthew 4:19) 

““And he who does not take his cross and follow after Me is not worthy of Me.” (Matthew 10:38 

“Jesus said to him, “If you wish to be complete, go and sell your possessions and give to the poor, and you will have treasure in heaven; and come, follow Me.”” (Matthew 19:21) 

The disciple is a learner. One who willingly sits under the teaching of another to grow in knowledge and experience. In our modern world, we call these people interns. Jesus called twelve men to intern under Him so that He could prepare them to become the leaders of the Church on Earth. For three years they would follow after Jesus, learn His doctrine, practice acts of service under His supervision, and eventually go out on their own to replicate His ministry. 

Discipleship is found throughout the Scriptures. For example, Samuel the Priest was first an intern for the priest Eli; Elisha the prophet served first under Elijah the prophet; young Timothy served under the Apostle Paul and eventually was sent to Ephesus in Paul’s place. Yet, the best example of all is offered by Jesus, who calls all those who believe in Him to continue in His Word, “If you continue in My word, then you are truly disciples of Mine; and you will know the truth, and the truth will make you free.”” (John 8:31–32) 

True church growth is based on the principle of discipleship. Jesus made disciples and His disciples made disciples. When the church stops making disciples we stop fulfilling our mission. Thom Rainer perhaps said it best, “Thriving churches have the Great Commission as the centerpiece of their vision, while dying churches have forgotten the clear command of Christ.”― Thom S. Rainer, Autopsy of a Deceased Church: 12 Ways to Keep Yours Alive