The end of the second verse calls the Trinity "Hope of all living." "Living" is sung with a melisma (F# E D), musically giving a sense of the entirety of that "all."
The fourth verse ends with the lines "Glory we offer, praise Thee and adore Thee, / Now and forever." Here, "forever" is sung with a melisma (G F# E D), musically giving a sense of duration.
The whole note in this phrase is the longest note value in the entire tune, and it also provides a sense of the breadth of "all living" and the duration of "forever."