The Torah is full of references to the “ketores,” the incense used in the Tabernacle. There are specific rules – the incense, for example, had to be continuously produced, a constant presence. But the meaning of the incense, and why it is so very important, is not directly explained in the text, nor widely understood.
I’d like to propose a very simple explanation for why incense is so critical for the tabernacle, the sine qua non for the gateway to holiness: it is the reminder of the basic building block of the relationship between Man and G-d. Here’s why: G-d blew the breath of life into Adam’s nostrils. The instrument we use to smell is where G-d connected to Adam, and so connects to each of us.
The incense, then, is constantly smoking because it is to constantly remind us of our creation and our connection to our Creator. Awareness of our connection to G-d is the precondition for building a relationship with Him.
In the Torah, nothing is good or bad in itself: what matters is how it is used. Incense is a link, a reminder of our creative origin. But the Torah uses the word for incense first when describing the destruction of Sodom and Gomorrah:
and, looking down toward Sodom and Gomorrah and all the land of the Plain, he saw the smoke[incense] of the land rising like the smoke [incense] of a kiln. (Gen: 19:28)
Which is precisely what happens when mankind is destroyed; that link is incinerated, the divine investment in mankind is lost.
We are commanded to be holy. The incense, reminding us of G-d blowing life in through our nostrils, reminds and aids us in that journey.