If we say we have no sin, we deceive ourselves, and the truth is not in us. (ESV)

If we say that we have no sin, we deceive ourselves, and the truth is not in us. (KJV)

Greek: ἐὰν εἴπωμεν ὅτι ἁμαρτίαν οὐκ ἔχομεν, ἑαυτοὺς πλανῶμεν καὶ ἡ ἀλήθεια οὐκ ἔστιν ἐν ἡμῖν.

Transliterated Greek: ean eipōmen hoti hamartian ouk echomen, heautous planōmen kai hē alētheia ouk estin en hēmin.

Literal Word for Word Translation: if we say that we have no sin, we deceive ourselves and the truth is not in us.

Commentary: The Gnostics claimed that because they had truth, that special knowledge which made them closer to God, that in effect they had no sin between them and God for which they needed to be cleansed by the blood of Jesus (v7). They saw the evil in the material world of no consequence in their ascendancy towards God – they were to leave that behind. John, however, clearly challenges that idea with verse 8 by saying that anyone who claims to have no sin is deceiving themselves, and rather than having the truth, they don’t have it. Many today who don’t even know what a Gnostic is also claim that they have no sin. They don’t say it because of a grand philosophy or any religious teachings (although some, such as a Buddhist, might), but because in their self-righteousness, they can’t stand to be told that they have sin that keeps them apart from a Holy God. Such thinking does not come from God!

John provides the following words from Jesus to a group of Jews in chapter 8 of his gospel, 44 You are of your father the devil, and your will is to do your father’s desires. He was a murderer from the beginning, and does not stand in the truth, because there is no truth in him. When he lies, he speaks out of his own character, for he is a liar and the father of lies. 45 But because I tell the truth, you do not believe me. 46 Which one of you convicts me of sin? If I tell the truth, why do you not believe me? 47 Whoever is of God hears the words of God. The reason why you do not hear them is that you are not of God.” The emphasized statement about Satan – “that there is no truth in him,” is interesting in its parallel with the point that for those who claim to have no sin, “the truth is not in us.” Truly, such who do not agree with Jesus are in agreement with the Devil and in effect are his children.

A few verses earlier in John, Jesus says, 31b “If you abide in my word, you are truly my disciples, 32 and you will know the truth, and the truth will set you free.” 33 They answered him, “We are offspring of Abraham and have never been enslaved to anyone. How is it that you say, ‘You will become free’?”
34 Jesus answered them, “Truly, truly, I say to you, everyone who practices sin is a slave to sin. 35 The slave does not remain in the house forever; the son remains forever. 36 So if the Son sets you free, you will be free indeed. 37 I know that you are offspring of Abraham; yet you seek to kill me because my word finds no place in you. 38 I speak of what I have seen with my Father, and you do what you have heard from your father.”
Jesus has the truth and that truth is what releases us from darkness and from enslavement to sin. However, being released from the penalty and power of sin by the redeeming blood of Jesus in no way means we have no sin at all. What is ironic is that since saying one has no sin is a lie, the very belief of it results in having sin!