What the Rav said:
Every time a person thinks about someone else, he should just praise him.
Generally, a person spends his time trying to pull down other people. When he manages to pull down everyone else, then he feels good. Because, if everyone else is a tzadik then he feels like he may as well just kill himself, G-d forbid.
Everyone is a tzadik and he isn’t?!? So, now he’s just going to kill himself.
However, a person who is normal thinks that everyone else is a tzadik.
If we degrade a Jew then we destroy the world.
We’re not talking here about Lashon Hara which is more serious than the three cardinal sins. Rather, even if a person just thinks in his heart something not good about another, he’s already destroyed the world.
My thoughts:
Around 20 years ago, I once had the great merit to spend a Shabbat in Gateshead, and to hear a shiur from on of the great teachers at the Yeshiva.
He gave a mashal regarding lashon hara which has always stayed with me.
He explained lashon hara as follows - you see two children standing on the pavement (sidewalk for our US readers) measuring themselves against each other to see who is the tallest. They’re around the same height, so it’s not clear who’s taller. Then, one of them has an idea. He makes his friend stand down in the road, in the gutter, and now they can measure themselves again. Naturally, the one sees that he’s now taller than his friend.
So too with us.
The reason we put others down is to make ourselves feel taller.