The dietary laws in Shmini parallel the prohibition given to Adam. As then, so now, a new era in the spiritual history of humankind, preceded by an act of creation, is marked by laws about what one may and may not eat.
Why? As with sex, so with eating: these are the most primal activities, shared with many other forms of life. Without sex there is no continuation of the species. Without food, even the individual cannot survive. These, therefore, have been the focus of radically different cultures. On the one hand there are hedonistic cultures in which food and sex are seen as pleasures and pursued as such. On the other are ascetic cultures - marked by monastic seclusion - in which sex is avoided and eating kept to a minimum. The former emphasize the body, the latter the soul. Judaism, by contrast, sees the human situation in terms of integration and balance. We are body and soul. Hence the Judaic imperative, neither hedonistic nor ascetic, but transformative. We are commanded to sanctify the activities of eating and sex. From this flow the dietary laws and the laws of family purity (niddah and mikveh), two key elements of kedushah, the life of holiness.
As someone who feels the call to pray but feels a tension between personal worship and public practice, perhaps it is best to characterize this as a larger process of Judaic transformation. Rather than push the practice of prayer in one direction, a celebration of Carlebacian hora dance, or to another monastic Yom Kipur confession warped in a talit, we should teach an imperative to navigate the spiritual and cultural world around us. Perhaps this call to pray is just this imperative that Sacks describes; otherwise we are just left with the obligation to pray which leads to the very beginning questions about the sad state of tefilla today.