I can only suggest reading "Death, Sacrifice, and Tragedy" which is
only 121 pages. It is impossible to reduce the content necessary to
expand on what he means about the sacramental nature of life. There is
also discussion about it in "The Idea of Perfection In The Western
World". Symbol and Metaphor are not terms found much throughout Foss's
other works. His treatment of life and death are very important
subjects. The Destiny of Man is another concept often used along with
sacrifice and service. The closest he comes to dealing with this
subject in "Symbol and Metaphor in Human Experience" can be found on
pages 83, 130 and 133. After reading those sections, you may find
other areas in the essay which are related to them. But for the best
way to grasp the "sacramental nature of life" is to read the book that
treats that subject thoroughly.