How do you think we’ll react to sin during the Millennium? We’ll be in our glorified bodies in the New Jerusalem, but we’ll have access to Earth. The Earth will have sinners, at least after the 1st generation has babies and they grow up. Some of them may be our loved ones. Do you think we’ll avoid sinners?
From 1 John 3:2 we learn that while we don’t know exactly what we’ll look like, we do know we’ll be like the Lord. He was not a sinner, but for the most part expressed love and compassion toward sinners. (The only exception was the “holier-than-thou” religious leaders.) Romans 8:29 agrees that God wants us to be conformed to the likeness of His son. That being the case, I would expect our attitude toward the people of the millennium to be the same as His was toward people when He was here before.