The Lubavitcher Rebbe had profound and beautiful teachings about light and good deeds, emphasizing their transformative power:
1. Light dispels darkness
The Rebbe explained that darkness is simply the absence of light, not a force to be fought directly. He said:
“Darkness, no matter how ominous … is merely the absence of light. … A thimbleful of light will therefore banish a roomful of darkness.” 
2. Every mitzvah brings redemption.
His clear message: even a tiny act of goodness can overcome great negativity.
The Rebbe taught:
“A single deed, a single word, even a single thought, has the power to tip the scales and bring redemption to the world.” 
The Rebbe insisted that doing mitzvot matters more than philosophical understanding.
His clear message: even a tiny act of goodness can overcome great negativity.
3. Light and deeds are interconnected
Ultimately, for the Rebbe, light and deeds weren’t separate—they were one and the same. By performing a mitzvah or act of kindness, we bring light into the world, banishing darkness and building towards redemption. Every gesture—no matter how small—is like a flicker that drives back the shadows.