After having become His disciple, do not continue to act like a slave. Don't allow the devil to continually beat you down. You are free. Walk in the freedom of the Spirit of God.
This is not, as some teach, a license to sin, but is freedom that is grounded in the knowledge that sin enslaves and, based on this knowledge, the desire to forever be free of its grip, free of its defilement, and to truly walk in the freedom of the Son of God.