5 This is the message which we have heard from Him and declare to you, that God is light and in Him is no darkness at all.
6 If we say that we have fellowship with Him, and walk in darkness, we lie and do not practice the truth.
7 But 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.
from Him (v.5) — Apostolic testimony was not given second hand. What the Apostles gave was not by hearsay, but was received directly from their Lord. — Vine, page 13.
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Light, perfect, pure light is God’s nature; He is absolutely holy with no darkness in Him at all. That God is light was manifested in the life of the Lord Jesus, for He was and is holy. Fellowship with the Father and the Son means, therefore, to have fellowship with light, and that excludes a walk in darkness. … But what is this walk in the light? It is not the same thing as walking according to the light. It does not mean to life a perfect and sinless life. Walking in the light is not the question of how we walk, but where we walk, and the place where the the believer walks is the light. It means to walk daily in His presence, with out will and conscience in the light and presence of God, judging everything that does not answer to that light. — Gaebelein, page 1175.
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God is light (1) Physically as He appeared to selected people (Exodus 33:18-23; 34:5-8; Acts 26:13,18; 1 Timothy 6:16); (2) Intellectually as revealed in His knowledge (Psalm 139:6; Romans 11:33-36); (3) Morally in His holiness and purity (John 1:4-5; 8:12; 12:35-36,46); and Spiritually in His truth which is real, genuine, and right. — Grace, page 2218.
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If (v.6) — This is the first of seven clauses introduced by “if” in the two sections from 1:5-2:6. The conditions thus laid down serve to distinguish actual profession from mere profession. — Vine, page 13.
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we (v.6) — The use of “we” in vs.6-10 is a rhetorical device where John identifies with his Jewish audience whether believes or unbelievers. — Grace, page 2218.
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Verses 6,8, and 10 begin with “If we say …” and show the attitude of a false profession of fellowship. Each phrase in these verses makes it clear that unbelieves are addressed. Verses 7 and 9 also begin with an “if” but show the parallels of true fellowship of believers in Christ. — Grace, page 2218.
walk (v.6) = the habitual or constant course of life, living, conducting one’s life
Some wonder if John could be referring to a believer as walking in darkness. By comparing additional verses, it become apparent that he could not. Those who “walk in darkness” are those who “hate their brother” (1 John 2:11), and those who hate their brother are murderers and do not have eternal life abiding in them (3:15). Therefore they do not have the Spirit of God or salvation. — Grace, page 2218.
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All the kingdom believers were walking “in the light” as part of their unction/anointing from the Spirit (1 John 2:20,27). All unbelievers had their position outside of Christ, and were walking in darkness. The children of God could not walk in darkness any more than the children of the Devil could walk in the light. [In Scripture], the consistent, uniform description of darkness refers to the unsaved. — Grace, page 2218.
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