Romans 6:18-23 Being then made free from sin, ye became the servants of righteousness.  I speak after the manner of men because of the infirmity of your flesh: for as ye have yielded your members servants to uncleanness and to iniquity to iniquity; even so now yield your members servants to righteousness to holiness.  For when ye were the servants of sin, ye were free from righteousness.  What fruit had ye then in those things whereof ye are now ashamed? for the end of those things is death.  But now being made free from sin, and become servants to God, ye have your fruit to holiness, and the end everlasting life.  For the wages of sin is death; but the gift of God is eternal life through Jesus Christ our Lord.

It is wonderful for a slave to be set free.  Isn't it funny that we, who have been set free, don't always make use of the freedom that God has given.  We go back into worry.  We go back into anger.  We go back into wanting things that aren't good for us, that destroy us.  But Christ has set us free.  When we do go back, the blood of Jesus covers us, and the Lord invites us to return to the path which leads to eternal life.  We yield our members as servants to righteousness.  Of course, we have no righteousness of our own, but God gives us His righteousness as a gift.  When we yield to His righteousness, He does His work through us.  We are set free from sin.