You are in a court of law and making accusations against your opponent. The judge demands that you present your evidence. You respond, “Well, actually, the evidence is that he didn't do it, but you can believe me because I believe he did commit the crime.” The judge belts out a hearty laugh and says, “Now wait a moment. You just said there is no evidence and in fact the only evidence is that your opponent did NOT commit the crime!? Why in the world would I believe anything you say beyond that?”
You can see how absurd such a scenario would be. Yet that is exactly what some so-called Bible authorities and Bible publishers do. The following is a direct quote from biblegateway.com: “[The earliest manuscripts and many other ancient witnesses do not have John 7:53—8:11. A few manuscripts include these verses, wholly or in part, after John 7:36, John 21:25, Luke 21:38 or Luke 24:53.]” And yet, they (the New International Version and numerous other translations) go right ahead and actually put those verses in their Bibles. Essentially what they are doing by including the text from John 7:31 through 8:11, is claiming that it was the writings of John, that it is part of his gospel, while at the same time saying the evidence speaks against it. When challenged, they have to admit that "the earliest manuscripts" do not contain those verses. And not only that but "other ancient witnesses" seem to discredit the charge that John wrote those.
In contrast, Jehovah’s Witnesses not only recognize but then act on that knowledge and do not include those verses in their Bible. You are welcome to believe what you want, that is what free will is all about. However, I will side with the ones who act in accord with what they know to be true. Excluding those spurious verses is the most honorable thing to do.