There are many styles of churches and ways of worship. Often people will describe the style of a church as liturgical or contemporary. However, this often comes out of a misunderstanding of the definition of liturgy. According to the Oxford Languages Dictionary, liturgy is "a form or formulary according to which public religious worship, especially Christian worship, is conducted." That is, liturgy is a formula or template of worship. With this definition in mind, contemporary churches are also liturgical (e.g. three fast songs, two slow songs, prayer, offering, preaching) but done differently.
But is liturgy important? Does it have the ability to develop or change peoples theology? To both questions, the short answer is "yes". Through worship music, people come into contact with good (orthodox) or bad (heretical) theology. Scott Ellington explains. "The Church expresses what it believes in worship even before these beliefs are studied or analyzed." (1)
James W. Farwell is Professor of Theology and Liturgy at Virginia Theological Seminary, argues that Christian liturgy is both a public and theological act.(2) In many of the historic denominations (Anglican, Lutheran, Presbyterian), a written liturgy is followed that includes the Nicene or Apostles Creed, prayers and call and response. It is through these liturgies that the congregation declares what they believe. Most Contemporary churches do not declare a creed or speak out grounded and ancient theological concepts through prayers and call and response. The people responsible for installing theological concepts are the songwriter and the preacher.
The best illustration I have was given about study theology (particularly Systematic Theology) was given by Rev. Dr Bruce Pass. He explained that it is not like a Rubix cube with only one solution, nor is it like an exploded diagram (think Ikea) where you find all the pieces and put them together. It is like a Tile Puzzle where there is always a gap. "Theology is about where you but your tensions and problems." It is where you leave the tensions (gap) that is critical. There are sometimes gaps that are just heretical (e.g. an over-focus on the ones of God that eliminates the three distinct persons of the Father, the Son and the Holy Spirit).
Some songs may have tensions in them that are ok to be left. But some may be wrong or (even if the lyrics are scripture).
How can we assess the theology of the songs we sing?
1. Do the lyrics make sense on paper?
The lyrics of the song must make sense on paper in their own right. Music takes us on an emotional journey, and it is easy to look over ambiguous lyrics. Our songs, our liturgy, needs to make sense in their own right.
2. Is it biblically and theologically sound?
Worship songs should be based on scripture and be contextual. Additionally, songs should be theologically sound (i.e. does an emphasis on Christ's humanity neglect His divinity? Does an emphasis on Father neglect Jesus and the Holy Spirit?). As said above, there will probably be some gaps or tensions. To find out what scriptures the song is based on, I recommend using WorshipTogether.
3. Who is being praised?
This is linked to number two, but it is worth mention. Is a one-sided version or image of God being worshipped, or is God in all His attributes being worshipped?
4. Who are is the song about?
There are a few songs out there that are primarily about "I". Should we ban all song with "I"? Definitely not! The Nicene Creed has "I" in it ("I believe in..."), but it is about God. Worship songs should be about God. The overuse of I can also make a sing un-relatable to the congregation (i.e. causing them to sing untruths).
5. Are the lyrics specifically Christian?
These songs are usually referred to as "Jesus is my Boyfriend" songs. That is, if you change the name "Jesus" to another name, it would be a hit love song. If this is so, there are probably better songs to sing.
All songs are not created equal. There is a responsibility for the Church to writ theologically sound songs that represent God in His (Father, Son, Holy Spirit) entirety.
(1) Keith Pecklers, Worship: New Century Theology (Collegeview, Minnesota: Bloomsbury Publishing, 2005), 164.
(2) James W. Farwell, 'Liturgy and Public Theology', Anglican Theological Review 102, no. 2 (Spring 2020): 219.