The structure of the piece goes as follows: The heavenly court is assembled and G-d sits at the head of the court as the Judge. What is G-d judging? He is judging our actions. In front of Him sit the Book of Life [and the Book of Death]. On Rosh Hashanah, it is written, and on Yom Kippur, the Book of Life is sealed, which determines who lives and who dies. We are then reminded that no fate is set in stone, which is why Unataneh Tokef states that tefilah, tzedakah, and teshuvah can avert the severity of the decree (Midrash Genesis Rabbah 44:12). G-d wants us to repent and return to His ways, hence why He gives us second chance. Finally, the poem calls attention to the fact that our origin is dust and our end is dust, and that G-d's existence is eternal.
After reading this piece, I can see why many Jews, myself included, have a problem with reading this piece. At first glance, Unataneh Tokef illustrates a Deuteronomic view of G-d gathering the names of everyone, figuring out who has been naughty and who has been nice, and adjudicating a simplistic version of punishment and reward that makes me wonder about the role of free will in Jewish thought, especially since the poem states that G-d determines "who will enjoy tranquility and who will suffer," "who will be impoverished and who will be rich," and "who will be degraded and who will be exalted."
A literal reading of the poem forces me to question some things in the poem. G-d is infinite and incorporeal, so at the very least, G-d is literally not writing in a book. Additionally, if we are to read the poem literally, does this mean that G-d actually predetermines who lives and who dies within a given year? I cannot imagine G-d would grant us the gift of free will, the very thing that makes us human, only to take it away. I also find it troublesome that tefilah, tzedakah, and teshuvah during these ten days would merit another year of life, although the Talmudic precept (Rosh Hashanah 16a) applies year-round. How is that tefilah, tzedakah, and teshuvah can prevent earthquakes, cancer, or airplane accidents? But let's say that performing tefilah, tzedakah, and teshuvah can actually avert the decree [of evil]. What about good people who do these three actions and die? Did people who died in the Holocaust, in a hurricane, or in a car accident "get what they deserved?" And what about evil people who completely ignore all of this: is it G-d's way of saying that evil people deserve another year of life?
How can one accept the poem literally? Poems aren't meant to be taken literally. That is why they are poems. Poetic license undoubtedly means usage of figurative language. Furthermore, given G-d's infinite nature, I feel compelled to read Unataneh Tokef figuratively, much like I would with any other prayer. On some level, we have to read Unataneh Tokef as if it were literal. However, we ultimately have to realize that Unataneh Tokef has to be understood figuratively. So what is Unataneh Tokef trying to convey here?
When the poem says G-d determines "who lives and who dies," this is not literal. G-d is omniscient. G-d's omniscience is not the same thing as saying that He is micro-managing, e.g., G-d is not literally determining judgment on Rosh Hashanah. What G-d is writing in the Book of Life [or Death] are not His rulings. Especially considering the line of "who [will die] in his due time and who before" (מי בקצו ומי לא בקוצו), G-d is metaphorically exerting His omniscience and merely describing what will happen in the upcoming year.
The imagery of the Books of Life and Death, as well as Unataneh Tokef as a whole, are to convey a sobering message: "We are not in control of everything. Life is ephemeral. You do not have forever. Repair that which is broken in your life and return to a sense of wholeness." Unataneh Tokef reminds us that there are certain things that are within our control and certain things outside our control. We cannot change when or how we will die. We read this poem realizing our own mortality and how frail life can be. The strong language and literary devices that Unataneh Tokef utilizes make us cognizant of this message.
Even with this frightening imagery of G-d determining who will live and die, the poem proceeds on an upside, mainly that our fate is not determined. We can do something to counter whatever wrong we have committed. Unataneh Tokef shows us three paths for spiritual transformation: tefilah, tzedakah, and teshuvah. Tefilah, commonly translated as "prayer," is our attempt to communicate with G-d. Since G-d is omnsicient, and G-d is not a vending machine, our role in prayer is that we are vessels for blessing. When we realize G-d's existence and the blessings He bestows upon us, prayer has the powerful effect of changing that which is around us because prayer changes us. Tzedakah, which is mistranslated as "charity," is an externality involving material wealth and shows how we relate towards others through humility and generosity. Teshuvah, which comes from the Hebrew verb "to return" (לשוב), is much more of a repentant process than saying "I'm sorry." It is a process of truly changing oneself for the better and returning to our true essence.
Performing the actions of tefilah, tzedakah, and teshuvah do not literally change whether we live or die in the upcoming year. G-d is constantly judging us (Talmud, Rosh Hashanah 16a). What changes is the effect of one's current spiritual condition. There is a personal transformation within us by performing these deeds: the blessing we receive, the forgiveness, the drive to become better human beings. The free will that we exert is a response within the confines of the events that are outside of one's control. G-d is a loving G-d, which is why shortly after the line about "tefilah, tzedakah, and teshuvah averting the decree", the poet reminds us that G-d does not desire death, but rather that one comes back to His ways and lives a full life.
The poem then continues on a more lowly note. "He [Man] is like a broken shard, like grass dried up, like a faded flower..."G-d exists and He is eternal. In comparison to G-d, we are "like whirling dust." Compared to G-d's existence, human existence is but a blip on the radar. Even in spite of human transience, the poem ends on a positive note: "[But] You are King, the Living and Everlasting." G-d makes it possible to connect with Him. G-d wants us to connect with Him, which is why He gives us the opportunity to do so.
This poem is not meant to cheat death or try to beg G-d for another year of life. Given the somber time of the year, it is also not meant to make us feel as if everything were hunky-dory and that the world is made of sunshine and rainbows. Unataneh Tokef is supposed to scare us and make us think in a profound manner. The poet wants us to recognize our humanity, as well as our vulnerabilities and frailties, at that given moment. Upon grappling, dealing with, and accepting our mortality, we are reminded that living a spiritual life means positively interacting with ourselves, with G-d, and with other human beings. Ultimately, the message behind Unataneh Tokef is to come to terms with what it means to be human and to have that realization awaken our souls.