Answer
In his first epistle, the apostle John deals with the assurance of our salvation: “I write these things to you who believe in the name of the Son of God so that you may know that you have eternal life” (1 John 5:13). Since he wants his readers to “know” they have eternal life, John provides a test of faith that we can use to examine whether or not we are truly saved.
In 1 John are various descriptions of the genuine believer. If a person knows Christ and is growing in grace, he or she will be generally marked by the following traits:
1. The believer enjoys fellowship with Christ and His redeemed people (1 John 1:3).
2. The believer walks in the light, not in the darkness (1 John 1:6–7).
3. The believer admits and confesses his sin (1 John 1:8).
4. The believer obeys God’s Word (1 John 2:3–5).
5. The believer loves God rather than the world (1 John 2:15).
6. The believer’s life is characterized by “doing what is right” (1 John 2:29).
7. The believer seeks to maintain a pure life (1 John 3:3).
8. The believer sees a decreasing pattern of sin in his life (1 John 3:5–6; 5:18).
9. The believer demonstrates love for other Christians (1 John 3:14).
10. The believer “walks the walk,” versus just “talking the talk” (1 John 3:18–19).
11. The believer maintains a clear conscience (1 John 3:21).
12. The believer experiences victory in his Christian walk (1 John 5:4).
Number 8 in the list above is that the believer will evince a decreasing pattern of sin in his or her life. Here is what John says:
“No one who lives in [Christ] keeps on sinning. No one who continues to sin has either seen him or known him” (1 John 3:6)
and
“We know that anyone born of God does not continue to sin; the One who was born of God keeps them safe, and the evil one cannot harm them” (1 John 5:18)
Some misinterpret these verses to mean that Christians can attain sinless perfection. After all, John says that “no one who lives in Him sins” (1 John 3:6, NASB) and that “no one who is born of God sins” (5:18, NASB). Based on those verses, they reason, sin must be a thing of the past. If you commit a sin, that’s proof that you are not saved, because Christians are sinless. But that is not what John is teaching.
We know that, when John writes that believers do not continue to sin, he is not referring to sinless perfection because of what he writes elsewhere in the same epistle. To believers John says, “If we claim to be without sin, we deceive ourselves and the truth is not in us” (1 John 1:8). So, we are all sinners, and we continue to struggle with sin even after we are saved. We will never know a total absence of sin until we are with the Lord in glory: “When Christ appears, we shall be like him” (1 John 3:2).
If John is not referring to sinless perfection, what does he mean that believers do not continue to sin? Very simply, he means that believers will not continue practicing sin as a way of life. There will be a difference between the old life without Christ and the new life in Christ. The thief who was characterized by his theft is a thief no more; he has a different way of life. The adulterer who was characterized by his immorality is an adulterer no more; his behavior patterns have changed. The child of God who was a former thief may still struggle with covetousness, but he no longer lives according to the pattern of stealing. The child of God who was a former adulterer may still struggle with lust, but he has broken free from the old life of immorality. “All who have this hope in [Christ] purify themselves, just as he is pure” (1 John 3:3).
The Amplified Bible brings out John’s meaning clearly:
“No one who abides in Him [who remains united in fellowship with Him—deliberately, knowingly, and habitually] practices sin. No one who habitually sins has seen Him or known Him” (1 John 3:6, AMP)
and
“We know [with confidence] that anyone born of God does not habitually sin; but He (Jesus) who was born of God [carefully] keeps and protects him, and the evil one does not touch him” (1 John 5:18, AMP)
The word habitually is key. A believer will struggle with sin and sometimes give in, but giving in to sin is no longer normative. As we grow in grace and in the knowledge of the Lord (see 2 Peter 3:18), we are being sanctified. As we are led by the Spirit, we will walk more and more in obedience to the Word of God.
If a person claims to be a Christian but lives in defiance of God’s Word, then that person is showing the world he or she is unsaved. No one who continues to live in willful sin knows God. Because continual sin is incompatible with new life in Christ, living in unrepentant homosexuality, idolatry, or falsehood is proof that no regenerative work of the Spirit has yet taken place in the heart, regardless of anyone’s claims to the contrary.
John gives us the reason why believers do not continue to sin: “No one who is born of God will continue to sin, because God’s seed remains in them; they cannot go on sinning, because they have been born of God” (1 John 3:9). A genuine Christian will not “deliberately, knowingly, and habitually” sin. It’s just not in their “spiritual DNA.”