In the first letter by the Apostle John to the saints in Asia, likely a circular letter to include the church at Ephesus, it has been well noted that he provides a series of tests or checks and balances for the Christian life. The centrality of these tests are: knowledge of God, growth in obedience, and love for others. In chapter 3, we see obedience approached from the negative side with an exhortation to avoid the “practice of sinning” in order to affirm the genuineness of faith. Note the passage below:
“4 Everyone who makes a practice of sinning also practices lawlessness; sin is lawlessness. 5 You know that he appeared in order to take away sins, and in him there is no sin. 6 No one who abides in him keeps on sinning; no one who keeps on sinning has either seen him or known him. 7 Little children, let no one deceive you. Whoever practices righteousness is righteous, as he is righteous. 8 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. 9 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. 10 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.” 1 John 3:4-10
Here we may observe the Apostle making 4 crystal clear assertions regarding those who make a practice of sinning, the first of which will be addressed in this post, and is the observation that those who make a practice of sinning are practicing lawlessness found in verses 4-5. We might say that practice is to give oneself over to repetitive or habitual action. This does not have in mind sinning in general, which we all do (1 John 1:8), rather it is a reference to the ongoing patterns or practice of sin. In other words, the life that is marked or defined by the downward spiral of sin.
Additionally, we read that all sin, not simply that committed habitually, is equated with the breaking of God’s holy law. Generally speaking this is God’s moral law, the requirements of which were written on the hearts of men from Adam onward (Rom. 2:14; conscience), summarized and codified in the 10 Commandments at Sinai, and written on the hearts of all those who through the blood of Christ have been redeemed and brought into the New Covenant by repentance and faith (Jer. 31:33, Ezek. 36:26-27, Heb. 8:10).
Inherently within this statement is the assertion that the Christian life is to be one marked by obedience. It has oft been assumed, in error, that the law and subsequent obedience to it, are to be eschewed from the life of a believer. As is evident from this and many other passages in the New Testament, the law clearly has a place in the life of a believer, lest we fall into the error of antinomianism. 
We would do well to remember the words of our Lord, “If you love me, keep my commandments” John 14:5. Our Apostle draws upon the language from his gospel in this very epistle when he writes, “And by this we know that we have come to know him, if we keep his commandments. Whoever says “I know him” but does not keep his commandments is a liar, and the truth is not in him.” 1 John 2:3-4. Furthermore, as we alluded earlier, one of the great promises of the New Covenant is God writing His law on the hearts of those who have been redeemed by the shed blood of Christ. We may conclude that the importance of obedience to God’s law in the life of the believer is paramount and to walk contrary to it is sin, namely lawlessness.
This first exhortation is supported by two clauses, one a reaffirmation that sin is lawlessness to help drive home the point and two that Christ, who is sinless, appeared to take away sin. This statement is meant to contrast Christ with sin and subsequently sin with believers. It is meant to offer a sober alert to the reader that where sin exists, it is contrary to Christ because 1. He is sinless and 2. He died to take away sins. Therefore stop sinning, more on that later.
Far too often we are given to light thoughts of sin and are often ignorant of the sinful patterns of behavior that flare up in our lives from time to time. In our passage above, the exhortation is clear: the practice of sinning is contrary to the life of a believer because it is contrary to God’s holy law, and subsequently to God Himself. It is contrary to the life of Christ and should be contrary to the life of a believer who is united to Him. And finally, it is the reason for which Christ died.
Thanks be to God that by His mercy He sent His holy Son, the Lord Jesus Christ, who fulfilled the law on behalf of all those who would repent of their sins and believe in Him. Christ, the only sinless One, the only One who upheld the law on every point has through His obedience credited, or we might say imputed, the righteousness that He earned to the account of those who have trusted in Him. As we have seen, the law still has a place in the life of a believer as a rule and guide, but it is no longer a heavy yoke on the neck. It is not a means to life, i.e. it is not a means to either justification or sanctification, each of which come only through Christ our Savior, but instead should be a delight (Romans 2:22, et.al.)
*Antinomian image credit: http://www.presenttruthmag.com/archive/XXVIII/28p1-11.htm Note: reference to this source does not imply endorsement.
