"The teaching of 1 John is concerned essentially with the conditions for true Christian discipleship. The two main divisions of the letter set out these conditions and exhort the readers to live in the light (1:5-2:29) as children of God (3:1-5:13)."27
John began his exposition of how his readers could enjoy fellowship with God by introducing the concept of God as light (1:5-7) and then explaining with four conditions what fellowship with God requires (1:8-2:29).
John began his explanation of what it means to live in the light by emphasizing that God is light.
1:5 This verse provides a basis for what follows in verses 6-10. It gives the standard against which the three following Christian professions fall short.
The "message"is the truth that Jesus Christ, the first "Him,"revealed to the apostolic eyewitnesses.
The figure of light that John used to describe God emphasizes His ability to reveal and His ability to deal with what the light of His holiness reveals (cf. John 1:4-5, 7-9; 3:19-21; 8:12; 9:5; 1:35-36, 46; Rev. 21:23).28God exposes and condemns sin (called "darkness"in John 1:5; 3:19; 12:35 [twice], and in 1 John 1:5-6; 2:8-9, 11 [twice]). The light figure emphasizes these qualities in God: His splendor and glory, His truthfulness, His purity, His self-communicative nature (cf. Ps. 27:1; 36:9; Isa. 49:6; John 1:9), His empowering activity (cf. John 8:12; 12:35; Eph. 5:8-14), and His right to demand (cf. John 3:19-21).29The light-darkness motif was common in both the Hellenistic and Jewish thought life of John's day and culture.30For John these concepts were mainly ethical (cf. Eph. 5:8-14).31
"Whatever other qualities this metaphorical designation may include, it clearly involves the intellectual and moral--enlightenmentand holiness. Just as light reveals and purifies, so by His very nature God illuminates and purifies those who come to Him. His nature determines the conditions for fellowship with Him."32
"As darkness has no place in God, so all that is of the darkness is excluded from having fellowship with God."33
John frequently emphasized his propositions by restating them in a negative form, as he did here.
1:6 John may have used the "If we claim"phrase in verses 6, 8, and 10 to voice the teaching of false teachers.34
"It is probable that these claims were real statements made by people in the church to which John was writing, and that they reflect the outlook of the people who were causing trouble in the church."35
John's reminder here is that the Christian who claims to have fellowship with God who is light (holiness) but disobeys Him is lying. A practicing sinner cannot have close fellowship with a holy God, though he can have a relationship with God (i.e., be a true Christian). God revealed this truth throughout Scripture. Action was a very important part of knowledge for John, and it must be for us as well (cf. James).
The Greek word translated "fellowship"(koinonia) here means sharing by two or more parties. It does not refer to sharing salvation.36John earlier said his aim was that his readers, who were Christians (2:12-14, 21, 27), should enjoy fellowship with the apostolic eyewitnesses that they did not then share (v. 3).
". . . all true fellowship' is predicated on apostolic doctrine."37
1:7 Walking in the light means walking according to the light. The idea is more where we walk than how we walk. Had John said "according to"the light rather than "in"the light, he would have been requiring sinless perfection for fellowship with God. We must be open and responsive to the light that we have, which increases as we grow in our knowledge of God's will.
"One another"evidently means God and us rather than our fellow believers and us in view of the context. We share the light in which God dwells. Another view is that John meant that we cannot enjoy fellowship with God if we neglect fellowship with other Christians.38
Two things are equally true of believers who walk in the light according to this verse: we enjoy fellowship with God, and we are experiencing cleansing from every sin.
"This ["every sin"] refers to man's sinful nature in general, although it may include the wrong acts which can occur even when a Christian is living in the light.'"39
"The thought is not of the forgiveness of sin only, but of the removal of sin. The sin is done away; and the purifying action is exerted continuously."40
God cleanses us at conversion in the sense that He will never bring us into condemnation for our sins. However, we need continual cleansing from the defilement that daily living brings because it hinders our fellowship with God (cf. John 13:10). The "blood of Jesus"is a metonymy for the death of Jesus.41
"What John has in mind here is the cleansing of the conscience from guilt and moral defilement which is so insisted on in the Epistle to the Hebrews (Heb. 9:14; 10:2, 22), and which takes a leading place among the saving benefits of the redemptive self-sacrifice of Christ."42
John articulated four fundamental principles that underlie fellowship with God to facilitate his readers' experience of that fellowship. One must renounce sin (1:8-2:2), obey God (2:3-11), reject worldliness (2:12-17), and keep the faith (2:18-29) to live in the light of God's presence.
"If the readers are to have fellowship with the Father and with the Son (v. 3), they must understand what makes this possible. They must know who God is in himself and, consequently, who they are in themselves as creatures of God. So the author first describes the moral character of God in terms of light (v. 5) and then goes on to deny three claims made by those who falsely boast of their knowledge and fellowship with God. The false positions are (1) moral behavior is a matter of indifference in one's relationship to God (v. 6); (2) immoral conduct does not issue in sin for one who knows God (v. 8); and (3) the knowledge of God removes sin as even a possibility in the life of the believer (v. 10). True tests' or evidence of fellowship with God or walking in the light are (1) fellowship with one another (v. 7), with subsequent cleansing by the blood of Christ; (2) confession of sin, (v. 9) which brings both forgiveness and cleansing; and (3) trusting that if we sin we have Jesus Christ as an advocate and sacrifice for our sins (2:2)."43
"It would be difficult to find any single passage of Scripture more crucial and fundamental to daily Christian living than 1 John 1:5-10. For here, in a few brief verses, the disciple whom Jesus loved' has laid down for us the basic principles which underlie a vital walk with God."44
