In the first three words of "Practice," Voigt establishes that this is a poem about emotional pain. "To weep unbidden" are words that describe pain from within, and as the poem unfolds and discusses death and then ends with a reference to loved ones, the reader understands that the speaker is pained by the loss of someone she loved. The speaker considers different views on what happens when someone dies. Perhaps they go to heaven, perhaps they merely rest, perhaps they somehow drift between the two worlds, or perhaps they return to earth in another form. These thoughts come so easily to the speaker that the reader cannot help but believe that the speaker has given these notions some thought, yet the tone of the poem indicates that she is still unsure of what she personally believes. It is a struggle for her to find peace in something, but uncertainty about the afterlife does not provide it.

The speaker's grief is not mild, as indicated by her uncontrollable weeping. It wakes her at night, and it makes time pass too slowly. She watches the clock as if seeing time pass will ease her pain, but it does not. Her question "is this merely practice?" seems to reflect a pessimistic and fatalistic view of what it means to live in the world. According to the speaker, enduring such pain might be practice for enduring future loss. In any case, by the end of the poem, the speaker has not found any real meaning in her pain or her loss.

The second half of the poem is concerned with various explanations for what happens after a person dies. The speaker comments that some people believe in heaven, while others believe that death is a state of perpetual rest. The latter may refer to the belief that there actually is no afterlife and that once the body dies, it is the end of the person's life entirely. In contrast, the idea of heaven is that when the body dies, the person's soul goes on to an eternity of peace and joy.

The speaker then considers the explanation offered by an unseen other, who states that after death, people float between the mortal world and the immortal world. This idea seems to open up the possibility of having the best of both realities, with the dead being able to keep a connection to loved ones left behind. In the speaker's tangent about five beetles in a peony, she remarks offhandedly that she would remember the image of the beetles if she came back as a bird. This introduces the idea of reincarnation and of returning to earth in a different form after death.

Faced with the experience of grief, the speaker cannot help but consider mortality and the circle of life. Voigt introduces the theme of mortality in several different ways. First, the speaker describes waiting for the clock to advance the day forward, even though time's passage brings no relief. Mortality is closely tied to time because only the mortal world is subject to the limits and challenges of time. Further, a being that is mortal will eventually run out of time. The presentation of the clock as an enemy supports this theme.

Another way Voigt approaches the theme of mortality is by exploring the speaker's uncertainty about immortality. The speaker is sure only of what she knows, which in this case is the inevitable pain of living in the world and facing her own mortality and the mortality of her loved ones. On the subject of immortality in the afterlife, she is...