Balderdash. The correct term would be we "celebrate" the liturgy. The notion of "assisting" is rejected by the very word "liturgy"--leiturgia in Greek, which means a PUBLIC act, something in which everyone "participates."

BTW, mjMcHale, your use of the phrase "assist at the Holy Sacrifice" suggests to me you do not in fact know in what sense the ACTION of the Eucharistic Liturgy is indeed a sacrifice, our sacrifice offered to the Father; and that "sacrifice" in this sense is probably the most primordial from of "worship" (the word you reject) in human history, uniting not only Christians and Jews but also polytheistic paganism and some aspects of animism. Sacrifice is simply the primordial human form of worshiping God by acknowledging our dependence on God.