My friend, Pastor William Cwirla, posted this somewhere…..just passing it along.
Why the Liturgy? First a definition and a disclaimer. By "liturgy" I mean the western catholic mass form as it has been handed down by way of the Lutheran Reformation consisting of the five fixed canticles – Kyrie, Gloria in Excelsis, Credo, Sanctus, and Agnus Dei. Pardon the Greek and Latin, but it sounds cool and we still use 'em. "Liturgy" also includes the assigned Scripture texts for the Sundays, feast days, and seasons. Most of what I will say about the liturgy of the Divine Service will pertain to "liturgical worship" in general.
Now, why do we worship according to the western, catholic liturgy?
Ten is one of those good numbers in the Bible signifying completeness, so I'll stop at ten. I'm sure there are more.