“If we say that we have no sin, we deceive ourselves,
and the truth is not in us.” (1 John 1:8, NKJV) 

Isaiah was never more acutely aware of his sin than when he stood in the presence of the glory of God. While the seraphim joined in heavenly chorus, “Holy, holy, holy is the LORD of hosts; the whole earth is full of His glory!” (Isa. 6:3), the prophet of God cowered in painful recognition of his sin and peril in the presence of the holy God. “Woe is me, for I am undone” (Isa. 6:5). Yet while Isaiah was powerless to do anything to save himself, God acted on his behalf so as to declare, “Your iniquity is taken away, and your sin purged” (Isa. 6:7). 

Our sin is never more glaring, never more grievous, never more hideous than it is in the light of the glory of God. The closer we draw to God, the more painfully aware we will become of our sin and shame. That realization is what lies behind John’s assertion: “If we say that we have no sin, we deceive ourselves, and the truth is not in us” (1 John 1:8). 

Truth is in accord with the light. It testifies to the way of God and the glory of the gospel. Ultimately, it speaks to union with our Lord Jesus who is the way, the truth, and the life. The truth being “in us” is a way of saying that we are of the light, that we are children of God. 

John takes it a step further when he says, “If we say that we have not sinned, we make Him a liar, and His word is not in us” (1 John 1:10). To suggest that we have no sin and have not sinned rejects the diagnosis and declaration of the word of God that we are all sinners. Such rebellion is an affront to the Author of the word, accusing Him of being a liar, much as the evil one did in the Garden of Eden (Gen. 3:4-5). 

Being in the light and of the Light carries with it a conviction of sin, righteousness, and judgment, and is therefore a hallmark of salvation. When John writes his epistle to those who believe in the name of the Son of God to assure them of eternal life (1 John 5:13), he includes awareness of sin. The unbeliever who walks in darkness may not perceive his sin or be pained by it, but the believer will be gripped by his sin and grieve over it with a godly sorrow. 

Isaiah found himself without recourse, a sinner in the hands of a holy and just God. But God acted. He directed that a coal burning with wrath be taken from the altar and applied to Isaiah. His sin was atoned for, his guilt taken away. That scene points to God’s provision for sin to come. 

John will declare this provision to us in a moment. For now, he wants us to feel Isaiah’s awareness and anguish, admitting our sin and our sinfulness. Such admission belongs to knowledge of eternal life in communion with the living God. 

In what way do we deceive ourselves and make God a liar by our denial of personal sin?