One of the delights of musical training is to see the connections between the discipline of music and that of other areas of life, most notably, theology.
I thought about this recently with regard to the fugue. A fugue is a musical form that has distinct parameters, and which great composers have exploited. Bach was, as in most things, the master.
A fugue begins with a single voice, playing a melody, called the subject. That very same melody comes in a few measures later and joins the first voice, which continues on. A third voice, and possibly a fourth joins as well. The “Little Fugue” in g minor is an excellent example of this.
The composer will do various things with the subject of the fugue, such as change it to major if it was in minor, or vice versa. Perhaps it will be inverted—turning the intervals of the subject upside down.
What does this have to do with theology? Scripture presents various themes; repeats and develops them throughout the books of the Bible. Consider the theme of redemption. In Genesis 3:15, we get a hint of the gospel in the promise of the “proto-evangel” when God tells the serpent:
I will put enmity between you and the woman,
and between your offspring and her offspring;
he shall bruise your head,
and you shall bruise his heel.
This is the first “sounding” of the subject of redemption. In Genesis 22, the sacrifice of Isaac, the theme recurs and is a little more developed. There we have the ram caught in the thicket, taking the place of Isaac. As Abraham answered his son, “God will himself provide the lamb,” Similarly, in Isaiah 53 we have the theme again repeated. One could find other themes, such as the Kingdom of God, or the covenant with the nation of Israel that are similarly “sounded” and developed throughout Scripture.
If we find a “melody” that clashes with the previous, perhaps there’s a wrong note. If one were to say “I have found a spot in Scripture that teaches we must work for our salvation” that would be inconsistent with the rest, and thus suspect. I don’t want to push the analogy too far, but the fugue subject has to be consistent with the others. Another way to look at this is the difference between systematic theology and biblical theology. We need both to ensure we’re faithful to God’s revelation.