In I John 2:28-3:10 the author writes to reassure the believers in their faith. He continues to recognize (3:7) the error of his opponents, but he wants the (3:2) believers to have confidence in Christ and His teachings and to avoid practicing sin. Thus, he strengthens their sense of assurance.
One, believers do not practice sin.
Those who are born of God, the believers, do not practice sin. In John's writings, the Father, the Son, the Holy Spirit, and the Word are all very closely related in bestowing new life. Our Triune God speaks His Word; we respond; and the Triune God and the Word abide in us. As a result of the new birth, the believer does not practice sin.
In I John tension exists between sin and perfection in the Christian life. In 1:8 John says, "If we say that we have no sin, we are deceiving ourselves, and the truth is not in us." Then in 3:6 he says, "No one who abides in Him sins; no one who sins has seen Him or knows Him." On the surface, these verses seem to contradict each other, but they do not.
As you read this message, you may think of many times that you have stumbled. You are not alone. Every believer occasionally makes mistakes. We do not live perfect lives. However, those who live for God do not deliberately, repeatedly, and continually practice sin.
Two, God's seed abides in you.
John says the believer does not practice sin "because His seed abides in him." In my view the pronoun "His" refers to God. The believer does not practice sin because God's seed abides in him. The "seed" may refer to the Spirit of God or to the Word of God. Actually, it makes little difference whether we regard the seed as the Word inspired by the Spirit or as the Spirit who inspires the Word. We easily could conclude that the seed refers to the Spirit and the Word. As a matter of fact, both the Spirit and the Word abide in the believer.
As believers, we are not left alone. We have the Word of God and the Spirit of God dwelling in us. In order for the Word to fully dwell, we must continually read and study the Word. The Word of God is spiritual food. We cannot live for Christ without it. And the Spirit of God illuminates the Word, and He helps us live up to the precepts of the Word.
Three, you have a new nature.
John says that the believer "cannot sin, because he is born of God." The reason why the believer does not persist in sin is that he is born of God. As Kistemaker (p. 303) says, "A person who is born of God cannot live in habitual sin." He cannot because he has a new heredity. This was the essence of what Jesus taught Nicodemus (John 3:1-15). As soon as the believer is quickened by the Spirit, he has a new heredity or new nature. The new heredity overcomes the old.
The old nature of many is bound by heredity, environment, and a wayward will. As the unbeliever lives in sin, he cannot overcome sin. His habits, thoughts, and patterns keep him from a higher way. Only when we are born of God, and have a new nature, can we be free. The person who is born of God can live free from habitual sin.
Four, the one who practices sin is of the devil.
In I John 3:8, he writes some strong and harsh words: "the one who practices sin is of the devil." When an unbeliever practices sin, we do not have difficultly with this verse. The unbeliever denies Christ and makes no effort to follow God's will or Word.
On the other hand, if a believer begins to practice sin, we are confronted with many issues. Some scholars may say that such a person was never born of God; others may say that the person was born again but has apostatized. Either way, the person is lost.
We must be careful, however, to judge believers. Only God knows when a believer comes under the judgment of I John 3:8. Many believers stumble, makes mistakes, then come to God in repentance, and are restored. As I John 2:1 says, we "have an Advocate with the Father, Jesus Christ the righteous."
Throughout our lives, opposition arises to our faith. The voices of false teachers and opponents are strong and persuasive. Initially, the disciples did not have the New Testament to guide them. They did have in their memories the teachings of Jesus. The Spirit brought all this to their remembrance. Now, we have the Spirit and the written Word.
Because the Spirit and the written Word dwell within us, we cannot habitually practice sin. We must beware of thinking too loosely about sin, but we must also avoid the legalism that leads to bondage. The Spirit and the Word will guide us every step of the way.