IT’S ONE OF the most famous stories in the gospel of John, though its authenticity is questioned. A woman is supposedly “caught” in the act of adultery. I say “supposedly” because both the man and the woman would have been subject to condemnation and punishment, but only the woman is dragged before Jesus. It smells like a setup, one more way for Jesus’ enemies to try to trick him into doing something that will get him into trouble.

I imagine the woman kneeling in the dust, eyes downcast. “Teacher,” the conspirators say with mock respect, “we caught her in the act! The law says we should stone her to death.” Then, with a smirk on their lips and a note of smugness in their voice, they spring their trap: “So…what do you say?”

But Jesus says nothing. They badger him for an answer, and finally he speaks: “Let any one of you who is without sin be the first to throw a stone at her” (John 8:7, NIV). I imagine the stunned silence of the scribes and Pharisees at this unexpected rhetorical ploy. They exchange glances, then slink away one by one until only Jesus and the woman are left.

Not even the Pharisees, it seems, in all their self-righteousness, would dare claim to be sinless — at least in such an obvious way. How then could some of the believers in John’s community say such a thing?

AS WE’VE SEEN, John asks his readers to consider three related claims and their consequences. The claims are probably not direct quotes, but aren’t purely hypothetical either. They represent the essence of what some members of the community have been thinking and saying, and their teaching has been having a corrosive effect.

Previously, we’ve looked at the first claim and John’s response. Anyone who claims to be a Christian is also claiming to have fellowship with God. But God is light — so how can someone who has fellowship with light habitually walk in the darkness of sin?

One possibility, of course, would be to somehow deny the reality of sin. That seems to be the gist of the two remaining claims John lays before his readers:

If we claim to be without sin, we deceive ourselves and the truth is not in us. If we confess our sins, he is faithful and just and will forgive us our sins and purify us from all unrighteousness. If we claim we have not sinned, we make him out to be a liar and his word is not in us. (1 John 1:8-10)

John’s previous contrast was between light and darkness. Here, it’s between truth and lies, truth and self-deception. But doesn’t just say that if we claim to be without sin, we’re telling an outrageous lie; he says, “the truth is not in us.”

Truth, in other words, is not just a logical property of statements, a distinction between fact and fiction. It’s a moral property of our character and conduct. In the Psalms, for example, God is described as truthful not because he only utters statements of fact. Rather, he is true to the covenant, faithful and dependable to his covenant people. The question of truth, then, is whether we live truly, in a way that aligns with the character and wisdom of God.

It’s impossible for us to know exactly what people were saying, though scholars have debated the issue endlessly. And again, not even the Pharisees would publicly claim to be sinless. But all of us are capable of self-deception. To the extent that we deny or downplay sin, we also fail to acknowledge it to ourselves or to God.

“CONFESS” DOESN’T MEAN “go to confessional.” At root, the word means to “say the same thing as” — in essence to agree with God that we have, in fact, sinned. That meaning, in turn, helps make sense of what follows. To fail to confess is to disagree with God. The central thrust of the gospel is God’s grace for sin, which comes through Jesus’ sacrificial death. Thus, if we deny the reality of sin, either in our own lives or somehow in general, we are calling God a liar, whether we intend to or not.

Again, it may be hard to imagine any believer today actually claiming to be without sin. But we don’t want to read John’s words as only pointing to a small and mixed-up group of people. We live in a world that doesn’t relish the very idea of personal sin. And we may be members of congregations where the word is almost never mentioned from the pulpit.

So before we move on to chapter 2 and what John teaches about walking in the light, let’s pause to consider the consequences of not taking sin with full seriousness. Because if we don’t recognize sin for what it is, can we know the real meaning of grace?