1 John 3:4-10 (ESV)
Everyone who makes a practice of sinning also practices lawlessness; sin is lawlessness.  You know that he appeared to take away sins, and in him there is no sin.  No one who abides in him keeps on sinning; no one who keeps on sinning has either seen him or known him.  Little children, let no one deceive you. Whoever practices righteousness is righteous, as he is righteous.  Whoever makes a practice of sinning is of the devil, for the devil has been sinning from the beginning. The reason the Son of God appeared was to destroy the works of the devil.  No one born of God makes a practice of sinning, for God's seed abides in him, and he cannot keep on sinning because he has been born of God.  By this it is evident who are the children of God, and who are the children of the devil: whoever does not practice righteousness is not of God, nor is the one who does not love his brother.
Everyone who makes a practice of sinning also practices lawlessness… Whoever practices righteousness is righteous, as he is righteous. I want to hone in on this word practice of. I think if this phrase was not used here I might just give up and make a practice of sinning. What I am saying is I know of myself that I am a sinner, and being a sinner I sin. I hate this sin. I hate the fact that I am short with people at times. I hate the fact that I can’t love others with the love that Christ has shown for me. I see sin inside of me. And these are not little sins to be ignored, especially when you are a pastor! Patience is a virtue that a pastor needs to develop, because it will be required of him if any are to hear the gospel in the midst of their sin. But though I sin, I do not practice sin. (Quite frankly, I don’t think I need to practice it as I have already perfected that art, as much as I care to anyway.) I gather here that practicing sin is a bit different than sinning. It is to know that something is a sin, and yet to continue to do it with glee, to know the right thing but do the wrong thing. It is to excuse sin, and make the gospel an excuse for sin. It is not to be bothered at all by sin. And I hereby do not want to lessen that guilt that comes with sinning vs. practicing sin. Sin is bad. Sin destroys. Sin needs to be repented of, so that it can be forgiven. There is forgiveness. Always forgiveness. But forgiveness comes with faith in Christ, as does righteousness. And faith, so fear, loves and trusts in God that faith hears also his law and practices it. That is practices righteousness.
Practices righteousness, now here you have something a bit odd, that is often misinterpreted. To practice righteousness is not the same as to have it perfected. I need to practice righteousness. The Christian needs to practice righteousness. Why? Because this side of glory the righteousness that he has will never be perfectly manifested in his practice of it. If one stops practicing righteousness one begins to practice sin. But the practice of righteousness is predicated on the fact that with faith in Christ we are righteous already. It is loving with the love with which he first loved us. And to practice righteousness is not just a matter or cleaning up our lives from outward vices which the world sees, but to confront the sin within us with the forgiveness of Christ. It is to swim in our baptism, and constantly return to the means of grace where by the regeneration of the Holy Spirit constantly works anew in our heart the saving faith in Christ who saved us from sin death and the power of the devil, not with silver or gold, but with his holy precious blood and innocent suffering and death. To practice righteousness is to lay hold on the death and resurrection of Christ day in and day out. To do anything else would be to practice sin.