There are parts of the liturgy that remain the same and some that change each week. Regardless, the use of the liturgy invites a common thread over a period of time, not as a straight jacket, but a means to confess the faith faithfully in Word, Sacrament, worship, prayers, etc. While a liturgical church often uses a hymnal, that is not a requirement. In reality, what I have found over the decades (some of which was wandering through the non-denominational route) is that liturgy gets us away from I have noticed: the desire or need or fear that we have to “come up with something new every week.” The common liturgical form allows stability (not my whims) but also freedom. There is also the “catholic confession of the Christian church” that unites us with Christians not just around the world, but throughout history.
Note that by following the three year lectionary cycle the congregation reads / hears about 75% of the entire Bible. How can that be bad? Most Protestant churches I have encountered in worship cover maybe 10-20% of the Bible. I’ll take the lectionary any day, rather than “What do I want to select this week?” The lectionary is set up with readings from Old Testament, Epistle, and Gospel, as well as a Psalm of the Day. The three year series follows Series A (Matthew), Series B (Mark, John), and Series C (Luke). The first half of the church year (1st Sunday of Advent through Pentecost) is focused on the birth, life, ministry, death, and resurrection of Christ, while the second half of the church year focuses on the growth of the church. Colors (paraments on the altar/pulpit and stole) help identify the season: Advent (purple or blue), Christmas (white), Epiphany season (green), Lent (purple), Easter (white), and the rest of the year green. Special festivals (red).
BTW over the years as I have taught congregations (and now pastors), I have discovered so many misconceptions about liturgy. When I finish Adult Instruction class in congregations (26 weeks long; the only Book allowed in class is the Bible), the common response is always: 1) What do we study next? 2) I truly appreciate the liturgy now, and 3) Can we receive the Lord’s Supper every Sunday?