Paul knew that the work of evangelism is only the beginning; the strengthening of God’s people through discipleship is equally a part of the Great Commission.
Christ is not going to have an ugly or a weak bride; he is going to have us strong - and beautiful; it is the work of discipleship to make God’s people strong and beautiful. This is done by teaching them everything that Christ taught his apostles.
This work is all-encompassing and holistic. In pursuing it we follow the Master.
Strong churches produce strong disciples.