John 8:1-8 will likely be italicized or in parentheses in your Bibles. What is the meaning of all this? Simply put, the earliest and best manuscripts we have of John's Gospel don't contain this passage. In fact, no manuscript reliably dated before 400 AD has this famous event where Jesus cleverly protects a woman caught in adultery from being stoned to death. So, what then are our options for how to treat this story? One option is to believe those who copied the manuscripts that have this passage accessed earlier and more reliable versions of John's Gospel than the manuscripts we possess today. That is possible, but certainly tenuous. Secondly, someone later down the road decided to invent this story, and later versions of John's Gospel copied down the revised narrative into different sections of John's Gospel (the manuscripts that have this story, place it in various locations in the Gospel). I do think this is more likely. How does this change the way we view this scripture, and the scriptures? Well, John's Gospel everywhere shows Jesus' brilliance, and we are very familiar with Jesus' ongoing disagreements with the Jewish religious leaders. In fact, even the rest of John 8 is an extended disagreement over Jesus' identity and the origin of the Pharisees opposition to the true Son of God. Jesus declares His opponents are children of the Devil and that is why they don't receive Him. So, John 8:1-8 isn't incredibly unique in its message. Also, just because there are a very few portions of our Bible (see also the ending of Mark's Gospel) that we are unsure are part of the books written by the original authors, doesn't affect our confidence in what is original. Also, like already mentioned, this particular passage really has minimal to no extra impact on our theology and practice. Every reasonable principle or application one could derive from this event is found elsewhere in scripture. If anything, the fact that Christian scholars look at the evidence, weigh it, and are willing to tell us the truth about a difficult text like this should give us all the more confidence in scriptures not in italics or in parentheses.