What the manuscripts show. The passage is absent from the two earliest papyri that contain this part of John (P66 and P75), from Codex Sinaiticus and Codex Vaticanus, and from many other early Greek manuscripts. Codex Alexandrinus and Codex Ephraemi are damaged at this point, but the missing leaves seem too short to have held it. The oldest Greek manuscript that contains it is Codex Bezae, copied about AD 400. It then appears in the great mass of Byzantine manuscripts and in the Latin tradition. Some manuscripts mark it with asterisks or obeli, and some place it elsewhere: after John 7:36, after 8:12, at the end of John, or in Luke after 21:38 or 24:53. That it was not part of the earliest form of John is the conclusion of most textual scholars (Strong).
But the story is old. Eusebius reports that Papias, early in the second century, told of a woman accused of many sins before the Lord. The third-century Didascalia, a church order, has Jesus send away a sinful woman with “neither do I condemn thee.” St Jerome says the passage stood in many Greek and Latin manuscripts in his day, and St Augustine suggested that some had removed it, fearing it would seem to excuse adultery. Many scholars think it records a real event from the life of Jesus (Moderate).
What the Orthodox Church reads. The editors of the Patriarchal Text printed it in regular type, explaining that, although it is not among the daily lectionary readings of John, it is found in enough of the Menologia, the books of readings for saints’ days, to be retained. The Church’s Gospel for Pentecost reads John 7:37–52 and then goes straight to 8:12, while John 8:3–11 is read on certain saints’ feasts. The Orthodox Church thus receives the passage as Gospel, while its own lectionary preserves a memory of its unusual history.
How translations handle it. The KJV and the Douay-Rheims print it as an ordinary part of John. The ESV and NRSVUE set it in double brackets with a note; the NIV prints it with a note that the earliest manuscripts lack it. The Catholic Church regards it as canonical.
What it does and does not change. No doctrine depends on this passage alone. It shows mercy and the call to repentance together: “Neither do I condemn thee: go, and sin no more.” Both halves are taught throughout the Gospels. The textual question concerns where and when the story entered John, not whether Christ forgives sinners.