This book from 1889, presenting a scholarly study of Christian hymns, has the following phrase:
It may be said, and with truth, that the Magnificat of Mary, the Nunc Dimittis of old Simeon, and, above all, that the Gloria in Excelsis Deo of the angels at Bethlehem, antedate this hymn of our Lord and His apostles. It may also be said, and with the same truth, that these furnished to the early Christians their earliest expressions of praise. But it appears that the Last Supper, with its pathetic union of Jewish and Christian ideas, was also the place at which the Psalms of David and the spiritual songs of primitive Christianity were united. The thought that this reveals is larger than these limits will permit us to discuss. It is in brief that as Jesus Christ came, “not to destroy, but to fulfil,” He designed to show to His Church that gratitude, love, trust, and adoration were to be combined in all future psalmody. The t’hillim of the Jew were to become the hymni of the Christian.
Now, according to the OED and Wiktionary, there seems to be further meanings of this word than that related to pity (perhaps the most used nowadays). I think the author does not intend to use the word in that sense. What is the intended meaning here?
PS: the paywalled/full version of the OED lists 6 meanings of pathetic.