At the Havdala ceremony marking the departure of Shabbat, we bless on a cup of wine and also on fragrances and on fire. (SA OC 298.)
The gemara relates the blessing on fire to the story that human fire was invented then: “On Motzaei Shabbat the Holy One blessed be He gave intelligence to Adam like that found on high; and he brought two stones and ground them together and fire came out of them” (Pesachim 54a). After the loss of our special spiritual level due to the sin of Adam and Chava, and the loss of the special spiritual glow of Shabbat, we are on our own, and have to make our own, material source of light.
The Mishna records a difference of opinion regarding the wording of this berakha. The school of Shammai say, “Who created the light of the fire”; the school of Hillel say “Who creates the lights of the fire” (Berakhot chapter 8). The Vilna Gaon explains that this dispute is not merely linguistic, but rather reflects a fundamental disagreement regarding exactly what we are praising HaShem for in this blessing.
The Gaon writes that according to Beit Shammai, the blessing is on the funda- mental concept of fire, which originated in the past (“created”) and is unitary (“light”). But Beit Hillel say that the blessing also praises HaShem for the actual fire which we enjoy. This kind of fire is constantly being brought into existence (“creates”) and is encountered in many varieties (“lights”) (Shenot Eliahu). Halakha is according to Beit Hillel.
This halakhic analysis corresponds beautifully with the Midrash we cited above. The source of this blessing is not the existence of fire per se, but rather the human ability to create and manipulate it, starting with Adam.
Even so, the wording of the blessing thanks HaShem for the ongoing creation of this potent natural force.
As Shabbat departs and we begin our work week, we are thankful for human ingenuity which enables us to harness the forces of nature to make our work easier and more productive. At the same time, we acknowledge that all of our supposedly human inventions and contrivances are ultimately being constantly provided for us by the Creator.