Our Gemara on Amud Beis discusses the ritual where the crimson thread was tied between the horns of the scapegoat, and another crimson thread was tied around the neck of the goat that was to be slaughtered. Once the goat was slaughtered, the crimson thread was hung from the entrance to the sanctuary. If the jews were forgiven, while the goat was being thrown off the cliff, miraculously the red thread hanging by the entrance to the sanctuary would turn white . The Jews would be able to see this.

There is a Fascinating Yerushalmi (Shabbos 9:3) which describes some interesting traditions about this process. Originally, each Jewish household would tie a crimson thread to the window of their own house, and it would miraculously turn white. However, because that no longer happened reliably to all, and so people should not be embarrassed, they discontinued this practice. After that, they began the custom of having the crimson thread hang from the entrance to the sanctuary. But since after time, it also did not turn white reliably, they discontinued that practice as well. The final and remaining practice was simply to leave the crimson thread between the horns of the scapegoat. As it was tumbling off the cliff, there would still be a chance to see if it turned white.

Shem MiShmuel (Zachor Bris, Aleph) raises the obvious question:

Why were the Sages trying to protect the Jewish people from the truth? It is important feedback to know that forgiveness was not been achieved. This way, there still would be a possibility for people to work harder, go deeper into themselves, and repent. Why would the rabbis hold this vital information back?

Shem MiShmuel felt the lesson from this to be so powerful, that he felt compelled to write it in Yiddish instead of Hebrew. He said, “זייא זענין געפאלען ביי זיך אין גאנצען”, which if my Yiddish serves me well, means that they would have had a complete and utter emotional downfall. He says, this would not allow them to achieve repentance at all, only hopelessness.

My friends, I believe these words speak for themselves about the line between healthy guilt and toxic despair.