Whosoever is born of God doth not commit sin; for his seed remaineth in him: and he cannot sin, because he is born of God. (1 John 3:9)
This is one of the many paradoxes found in Scripture. How can a Christian not sin and yet sin? The Greek phase “does not commit sin” is in the present tense denoting continuous action or, in other words, a “habitual” practice of sin. The rest of the verse explains why the child of God cannot sin: “for [God’s] seed remaineth in him: and he cannot sin, because he is born of God.”
Paul tells us that true Christians, those who are “born again” are given a new nature: “Therefore if any man be in Christ, he is a new creature: old things are passed away; behold, all things are become new” (2 Corinthians 5:17). That means our old nature has been done away with: “I am crucified with Christ: nevertheless I live; yet not I, but Christ liveth in me: and the life which I now live in the flesh I live by the faith of the Son of God, who loved me, and gave himself for me” (Galatians 2:20). When we are truly “born again,” we are given a new nature so that we have the ability not to sin, but that ability comes from the indwelling power of the Holy Spirit (“Christ liveth in me”). We have the power not to sin, yet we keep our sinful flesh that retains that bent toward sin. Paul expresses his dilemma this way: “O wretched man that I am! who shall deliver me from the body of this death? I thank God through Jesus Christ our Lord. So then with the mind I myself serve the law of God; but with the flesh the law of sin” (Romans 7:24-25).
For the Christian, both natures exist within the individual. Someone who claims to be a Christian and continues in “habitual” sin without remorse has not truly been regenerated, i.e., born again. An authentic Christian instantly recognizes when he sins (because the Holy Spirit within him makes him aware) and immediately turns to God for forgiveness, and “If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness” (1 John 1:9).