As a bochur, Reb Simcha Werner questioned the Rebbe why it was so bad if he did an aveira once in a while. The Rebbe gazed at him strongly and gave him a contemporary example.
Reb Simcha Werner related:
Once, at a Farbrengen, I heard the Rebbe talk powerfully about the importance of a Yid conducting himself with kabbolas ol.
Around that time, I had a yechidus with the Rebbe. I couldn’t grasp the importance of total subjugation, so I asked, “What difference does it make to the Eibershter if once in a while I commit an aveirah?”
Usually, the Rebbe looked down at the table in yechidus. Now the Rebbe looked up and gazed at me like I had never seen before. I became terrified, I couldn’t look at the Rebbe, so I lowered my eyes.
The Rebbe spoke for a while, but I only recall one point:
“Imagine someone who generally respects President Johnson,” the Rebbe said, “but just sometimes, very rarely, slaps him in his face…”
(Teshura Werner Adar 2 5779)
From The Weekly Farbrengen by Merkaz Anash
Thank you for posting this except. Very powerful.