In I John, the Apostle John begins his letter with personal experience. "That which was from the beginning, which we have heard, which we have seen with our eyes, which we have looked upon, and our hands have handled, of the Word of Life; (For the life was manifested, and we have seen and bear witness, and show unto you that eternal life, which was with the Father, and was manifested unto us." Reader, our doctrine, our gospel, our preaching, our teaching, our life must be matters of personal experience with the Lord Jesus Christ. We cannot settle for second hand information or yesterday's manna. God reveals everything that God has for a man through the Lord Jesus Christ. This revelation of God in Christ, and this revelation alone, is true spiritual fellowship. John continues and declares why he has written, (I John 1:3-4) "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. And these things write we unto you, that your joy may be full."
The first and continual thing that God teaches us is that He is Light. "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 (I John 1:5)." In Him, there is no hypocrisy, no guile, no deceitfulness, and no impurity. He alone is goodness, holiness, justice, faithfulness, kindness, and truth. All of His ways are righteousness, and His wisdom extends over all of His works. He is as wise and sovereign, as He is eternal. (Job 12:12-13) "With the ancient is wisdom; and in length of days understanding. With him is wisdom and strength, he hath counsel and understanding."
This great God, is the Lord Jesus Christ, the Light (John 1:1-4). He is Deity and purity manifested in the flesh. He is the heart expression of the very essence of otherwise unknowable God. "No man hath seen God at any time; the only begotten Son, which is in the bosom of the Father, he hath declared Him (John 1:18)." His conception was purity. The Holy Ghost came and overshadowed Mary in His conception (Luke 1:35). He did not receive any of His purity from her virginity. Her virginity typified His purity; her virginity fulfilled the miraculous prophecy of Scripture; and her virginity clarified His Divine origin. But the eternal Son, without any compromise of His essence, was joined to His spotless humanity by the overshadowing power of the Holy Ghost. Being conceived and brought from the womb with no sin, our Lord Jesus Christ was pure in all of His temptations. While trials reveal our weakness, they revealed His perfect faith. He said, "… the prince of this world cometh, and hath nothing in me (John 14:30)." Our Lord Jesus was purity in His death. Even while bearing the enormous iniquity of God's elect, He suffered upon the cross with no sin. Even while He bore our judicial punishment and the guilt of our sin within His conscience, He trusted God His Father perfectly. Yea, reckoning His Father to be infinite purity and faithfulness, "… when he was reviled, reviled not again; when he suffered, he threatened not; but committed himself to him that judgeth righteously (I Pet. 2:23)." He is called "… the Holy One and the Just…" for He is the only Man, since Adam's transgression, that is worthy of God's love. And, God shall judge the world by Him. "Because he hath appointed a day, in the which he will judge the world in righteousness by that man whom he hath ordained; whereof he hath given assurance unto all men, in that he hath raised him from the dead (Acts 17:31)." Our Lord Jesus Christ is Light, and in Him is no darkness at all.
Walking is darkness is denying what you've just read concerning the Lord. Walking in darkness is denying that God is as infinitely pure as He has declared Himself in the Word. Walking in darkness is trusting that you can somehow stand before the judgment seat of Christ and enter in with your own righteousness (Matt 22:11-13). Walking in darkness is declaring that God will accept your imperfect works and can wink at your sin. Walking in darkness is declaring that God is a fool for punishing His Son because you can weep enough and do enough to clear yourself of sin (Gal. 2:21). Walking in darkness is you calling God a liar and favorably measuring yourself beside the Lord Jesus Christ. "If we say that we have fellowship with him, and walk in darkness we lie, and do not the truth (I John 1:6)."
But, if we confess our sins, then we walk in the Light. (I John 1:9) "If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness." Confession of sins is the way to holiness. The confessor comes to God unworthy of God's favor and admits that he, in all of his ways, falls short of the Lord of Glory. The confessor recognizes that he is worthy of the most painful affliction that God has promised in His Word. We have nothing to pacify His anger, nothing to satisfy His justice, and no hope of improving ourselves for future grace. Our promises to do better next time are worthless. The confessor, like the leper that came to our Lord Jesus acknowledging his own internal corruption, surrenders himself entirely to God's ability to save him as a sinner. "And, behold, there came a leper and worshipped him, saying, Lord, if thou wilt, thou canst make me clean (Matt. 8:2)." The confessor worships God by believing what God has declared in His Son.
God declares Himself Faithful and Just to forgive us our sins and to cleanse us from all unrighteousness. He is Faithful to forgive because He is Light. He does not lie, in Him is no deceitfulness, and He shall surely fulfill every promise. God the Father is as faithful to the confessing sinner as He was to the Lord Jesus Christ in all of His life, death, and resurrection. Secondly, God is just to forgive us our sins. Justice demands death for every transgression, and Christ's blood was shed as death for the sins of others (Heb. 9:22). Justice demands purity for every recipient of grace. Christ's resurrection declares Him to have been obedient unto death, and His justified Person is the source of our newness of life (Rom. 6:8-13). Therefore, through the merit of His blood, every confessing sinner receives forgiveness of sins, and this forgiveness always produces cleansing or the fruit of the Spirit. The new man is strengthened by the revelation of grace, and the old man is subdued through the power of the Spirit (Rom. 8:11-13; Col. 3:10; John 13:3-5).
It comforts me greatly that forgiveness and cleansing comes through confession. In fact, the Apostle John wrote these things that our joy might be full (I John 1:4). That we might know and continually enter the glorious revelation of God fellowshipping with sinners in the blood of His Son –continually forgiving us our sins and cleansing us from all unrighteousness. "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 (I John 1:7)."