Jesus is talking to Jewish believers and makes the promise that if they are faithful to his teachings then they will really be his disciples. A disciple is a student -- one who is learning from the master. Later they may be "sent" to do God's work. Then they are called apostles. We should all be disciples, but some of our members may become apostles! Exciting thought!
What are we set free from if we are disciples? We are set from ignorance, from the desire to sin, from impure thoughts and deeds. We are no longer bound by Satan if we know the truth of God -- which is Jesus.