Just as Christians should have more depth since they have God living inside of them, so should our music. Songs that continually have the same chords sounding over and over do not reveal much glory. This is like living in a world where just the color red exists. How boring! One would never know the exhilaration of looking at the bright yellow and orange sun. Yet God made that sun and wants us to experience the emotion it brings out in us. Likewise, He made a whole world of harmony that we are not experiencing. We have to bring it back into our music.
Our music should sound different than the rest of the world. Not just in our lyrics, but also in the music itself. Search for ways that harmony and melody reflect God's character and His creation. Then reveal that through what you write.
You can glorify God in more ways than preaching His name. A gardener doesn't glorify God by spelling out the name "Jesus" in a flower bed. It's more complicated than that. He meditates on reality. What is it about soil that relates to Him and how He made the world? What is it about the growth of a flower that reflects God's character and how He works?
How can you do the same with the songs you write?