Why is it that simcha, joy, breaks barriers and changes things?
The Tzemach Tzedek, the third Lubavitcher Rebbe, once visited Jewish soldiers in the czars army.
They said to him, “Rebbe, we worked to shine our buttons on our uniforms in your honor. Now please polish our souls that have become coarse and heavy.”
These were soldiers who were captured as little children and forced to work in the army.
The Tzemach tzedek told them that the soul is polished through earth, words of tehillim and through tears.
One soldier told the Tzemach Tzedek that when the soldiers go to battle, they march with a happy triumphant tune. “a war is won with a song of victory, “he said. “not with tears”.
The Tzemach Tzedek said that soldier is right. “A soldier follows orders and does so joyously. Even if he needs to advance to a dangerous position, he goes forward with a song of joy.”
This world is a war. We are constantly battling our own yetzer haras. We battle the environment, impurity, evil, problems and challenges of society. We are like soldiers. A Jew who serves G-d with joy
Is victorious over all enemies, trials and obstacles.
The face a person presents to Heaven draws down a similar reaction from Above. When a person is in a state of sadness, depression, fear or anger, this brings about judgments and more unhappiness.
But if a person is happy, and goes forward in life with joy, this is the way to be victorious in life against all our battles. Our simcha sweetens any denim and harshness in the Heavenly realms. This is how to win the war of galut, and break down the walls of exile and bring redemption.