Tanya Chapter 36 part 4

The Revelation at Mount Sinai broke all barriers, and we beheld the Divine. That condition was only temporary -- the sin of the golden calf brought denseness back to the world. Still, with the profound revelation of the Torah, we received the strength to transform the darkness into light, and this time for good. A time is coming when the fleshly eye will perceive the Divine and every creature on this earth will perceive and know G-d.