Chapter 7 gives earthly life an unusual weight by saying it can change more than the present generation. A person’s course can help liberate, advance, or console ancestors whose own paths remained unfinished.
That gives one lifetime leverage beyond its visible size. The present is not just a moment between past and future; it is a place where unfinished history can be helped.
The claim also resists private spirituality. If my life can affect the dead as well as the living, then faithfulness is never merely about my own peace.