We walk in the light by being transparent before the Lord.
5 This then is the message which we have heard of him, and declare unto 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 the truth:
7 But if we walk in the light, as he is in the light, we have fellowship one with another, and the blood of Jesus Christ his Son cleanseth us from all sin.
8 If we say that we have no sin, we deceive ourselves, and the truth is not in us.
9 If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness.
10 If we say that we have not sinned, we make him a liar, and his word is not in us.
There is walking in the light, or walking in darkness.
There is having fellowship with God and other believers, or not having fellowship.
There is confessing our sin, or denying our sin.
There is having truth in us, or being deceived.
3 That which we have seen and heard declare we unto you, that ye also may have fellowship with us: and truly our fellowship is with the Father, and with his Son Jesus Christ.
4 And these things write we unto you, that your joy may be full.
John writes so that all may have fellowship with God, and with believers. This is an appeal, to leave the darkness for the light.
Isaiah 49
8 Thus saith the Lord, In an acceptable time have I heard thee, and in a day of salvation have I helped thee: and I will preserve thee, and give thee for a covenant of the people, to establish the earth, to cause to inherit the desolate heritages;
9
That thou mayest say to the prisoners, Go forth; to them that are in darkness, Shew yourselves. They shall feed in the ways, and their pastures shall be in all high places.
John 3
16 For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life.
17 For God sent not his Son into the world to condemn the world; but that the world through him might be saved.
18 He that believeth on him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God.
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And this is the condemnation, that light is come into the world, and men loved darkness rather than light, because their deeds were evil.
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For every one that doeth evil hateth the light, neither cometh to the light, lest his deeds should be reproved.
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But he that doeth truth cometh to the light, that his deeds may be made manifest, that they are wrought in God.
Why does Isaiah say to those in darkness, Show yourselves? Because when we are conscious of our sin we want to hide. Same as Adam. God wants us to stop hiding from Him.
Much love!