All too often, we just aren't doing discipleship AT ALL. That's a tragedy but likely also the reason that many of our Evangelical churches are failing. We fail not so much by declining attendance but by becoming more and more like the rest of the world.
As Evangelicals, we should be defined by two commands, typically known as the Great Commandment and the Great Commission.
The great commandment is actually two where ( in Mark 28) Jesus said, "Hear, O Israel, the Lord our God, the Lord is one. Love the Lord your God with all your heart and with all your soul and with all your mind and with all your strength. The second is this: 'Love your neighbor as yourself.'There is no commandment greater than these."
However it is the Great Commission that is largely ignored by the church. After Jesus rose from the dead he spent another fifty days teaching and preparing His disciples. Just before he ascended into heaven, Jesus gave them and us a command: "All authority in heaven and on earth has been given to me. Therefore go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, and teaching them to obey everything I have commanded you. And surely I am with you always, to the very end of the age."
Becoming a disciple is not the same as becoming a member of a church like it was some kind of club. The word disciple means "to follow" and "to learn". It also has the connotation of adhering to a person and imitating a person. That person is none other than Jesus.
The early church grew because believers invested in other people and made disciples. Many churches today invest in buildings and hope that some educational program will make disciples. Discipleship however has always been relational and involved reaching and mentoring and teaching. Just like Jesus!