1 John 3:8-9

He who does what is sinful is of the devil, because the devil has been sinning from the beginning. The reason the Son of God appeared was to destroy the devil's work.

(v8, NIV)

Do not continue in sin. Instead, do what is right. Are you not of him? Do you abide in him? Do you know him? Well, the real question is, do you do what is sinful? If you do what is sinful, you are of the devil. The devil has been sinning from the beginning; just think of the serpent in the Garden of Eden. So if you keep on sinning and doing what is sinful, you are of the devil. If you are of the devil, can you also claim to be of God? God is light and in him is no darkness at all.

No one who is born of God will continue to sin, because God's seed remains in him; he cannot go on sinning, because he has been born of God.

(v9, NIV)

Instead of being of the devil, there are those who are born of God. We are all of the devil because we all sin. Earlier, there are those John refers to who keep on sinning. These who keep on sinning do not live in Jesus.

In reply Jesus declared, "I tell you the truth, no one can see the kingdom of God unless he is born again."

(John 3:3, NIV)

In John 3, Jesus is talking to Nicodemus and he talks about being born again. We all sin and we all begin as ones who are of the devil. However, there are those who cease to be of the devil and are born of God. These who are born of God do not keep on sinning. In fact, since he has been born of God, he cannot keep on sinning. Those who are born of God and of God cannot continue in sin. It just doesn't work; this is the power of God over us and against the works of sin and the devil.