The סְפִירוֹת (“Sefiroth” – emanations) are the channels through which divine energy (אור אין סוף ”Ohr Ein Sof” – divine, primordial light) flows or shines. As the world degenerates because of sin, the flow ceases. This can be seen as, HaShem averting His gaze as he cannot behold wickedness, and humans also detaching themselves from the receiving end of this spiritual light, through לשון הרע (“Lashon Hara” – evil speech / slander), שנאת חנם (“Sinat Chinam” – baseless hatred), impurity, violence and other sin, all generating low frequencies of coarseness and worldliness, becoming misaligned, out of tune from spirituality. We humans routinely place other idols in place of HaShem, be they materialism, pleasure, selfishness, egomania, narcissism… the varieties are manifold. We set them up to substitute the one Maker of the universe, because He is too lofty, too pure, or we’re simply too embarrassed.
If the flow of divine light would stop entirely, the creation would be destroyed entirely. The שערים (“Sha’arim” – gates) were wide open initially, at the time of the patriarchs. As humanity falls deeper into the entanglements of sin (primarily the Jews, but also the nations), the openings diminish, the energy reduces, the gates begin to close and the outflow of energy gets reduced. HaSatan can block the divine energy, and is also enabled to divert the divine energy to himself, growing his power.
Tikkun (Repair work) that can intensify the flow again has three devices: Mitzvoth, Tshuva (repentance) and suffering. As the gates close, HaShem opens new חַלּוֹנוֹת (“Chalonoth” – windows) to compensate, as the Jews go into גָּלוּת (“galuth”, exile), in their own land, or evicted into diaspora. By further deterioration of world affairs, these windows close as well, down to a “nanometer” – i.e., a tiny slit that only allows through the minimum amount of light to sustain merely the foundations of the world. This is the time of the greatest darkness.
Then, HaShem will open the gates again, ushering in the beginning of the messianic era. We are very close.
We are right at the onset of this process of redemption.
Go out of the exile with mercy.