1That which was from the beginning, that which we have heard, that which we have seen with our eyes, that which we saw, and our hands touched, concerning the Word of life 2(and the life was revealed, and we have seen, and testify, and declare to you the life, the eternal life, which was with the Father, and was revealed to us); 3that which we have seen and heard we declare to you, that you also may have fellowship with us. Yes, and our fellowship is with the Father and with his Son, Jesus Christ. 4And we write these things to you, that our joy may be fulfilled.
5This is the message which we have heard from him and announce to you, that God is light, and in him is no darkness at all. 6If we say that we have fellowship with him and walk in the darkness, we lie and don’t tell the truth. 7But if we walk in the light as he is in the light, we have fellowship with one another, and the blood of Jesus Christ his Son, cleanses us from all sin. 8If we say that we have no sin, we deceive ourselves, and the truth is not in us. 9If we confess our sins, he is faithful and righteous to forgive us the sins and to cleanse us from all unrighteousness. 10If we say that we haven’t sinned, we make him a liar, and his word is not in us.
This verse and the two following address the issue of sin in the believer’s life in light of what has just been said. John accomplishes this contrast by beginning this sentence with the same words as 3:3, though the English tends to translate them differently. So both could be translated by “everyone who” or “whoever.” His use of this construction indicates that he is stating a principle.
The principle is that a person choosing to sin is being lawless. The nature of sin is to reject order, to be lawless. Those who choose a lifestyle of sin are therefore lawless individuals. John’s point is that the opposite of a pursuit of holiness is a lifestyle of sin. This stands in contrast to Jesus’ purpose in His incarnation. It also provides a reason for the believer to pursue personal holiness through obedience and confession of known sins (1:9).