Sorry for the delayed response. I have been doing some research to give you the best answer I can.
The short answer to your question “is there a spiritual component to the way our biology functions” is yes. As Christians we believe we are embodied souls meaning there is a dualism to an extent (spirit and physical/biological); however, we see them working together. We know there is a spiritual realm that can affect our physical realm and we know that the physical choices we make can affect our spiritual realm. For example demonic oppression (spiritual —> biological); and on the other hand we know that sex is a physical/biological act and yet it is also spiritual according to the Christian worldview. If we are not careful, as we have seen in history, we can fall into a gnostic understanding of things and really diminish the physicalness of our reality. But Christ had a resurrected body and so will all of those who follow him. We cannot diminish the physicality of our existence. God is the author of our biology. Moreover, it is understood that disease and sickness are a result of the fall (spiritual) and yet its affect pervades the physical/biological.
How does this play out within our biology? As far as I can tell, its a mystery and up for debate. We see that when Christ healed people it was spiritual, but it actually altered the biology too, right? A withered hand was restored, leprosy was washed clean, eyes were opened, and even a dead man was raised to life. The spiritual has a way of altering the physical. Does this mean that those who are spiritually “sick” will have physical problems as well? I would say possibly, but we cannot say this is always the case.
For example, we see in John 5, that Jesus heals a man at the pool on the Sabbath. After this man is healed, later on Christ says in vs. 14 “Sin no more, that nothing worse may happen to you.” So it appears his sin (spiritual) may have a role in his sickness (something worse). But it is possible for this man’s sickness to be due to his sin without this verse suggesting that ALL sickness is due to personal sin. For example, just 4 chapters later in John 9 we see the opposite. A man who was blind from birth passed by and the disciples asked Jesus “who sinned, this man or his parents, that he was born blind?” Yet Jesus answers “It was not that this man sinned, or his parents, but that the works of God might be displayed in him.” (vs. 2)
The Bible is more nuanced than throwing blanket statements as a whole. Are the spiritual and biological related, yes! What is their relationship, mysterious. When it comes to the functioning of our bodies, and if an abnormality/sickness is present, I would be very cautious in saying “this is a spiritual attack.” I say that not to diminish the spiritual realm, I just think those words can be confusing at times when someone is really going through sickness. I think we in the west tend to diminish the spiritual far too often, and yet we know many eastern (more traditional) cultures have blamed all things on the spiritual without any acknowledgment of the biological. Could there be a marriage of the two? I think so. I think as Christians we need to address both the spiritual and physical because we are embodied souls and both parts matter. This is why Christ didn’t just meet the physical needs of the sick and poor, he met their spiritual needs as well.
On a different note, getting into the idea of spirituality and biology, many have asked can spirituality be explained by biology? And for this question I am going to be referring a lot to the work of Dr. Sharon Dirckx. She actually just came out with a book called “Am I just my brain?” and she is also a speaker for RZIM. In fact, on Tue the 10th of Sept she will be doing a live event at RZIM HQ specifically on her book. You could watch it live online, I would highly recommend it.
In 2004, Dean Hamer wrote a book called “the God gene: How faith is hardwired into our genes.” But this book isn’t taken very seriously within the scientific community because the correlations were mild and not specific to religion, plus genetic influence/traits are often polygenetic (not from one but multiple genes). Additionally, environmental influences are stronger than genetic but even “upbringing” doesn’t explain everything (ie agnostic parents with a Christian kid or the opposite). We also know that Neuroscience has shown that there is no “God-spot” within the brain that if stimulated resulted in a spiritual experience.
But we do know that spiritual practices (prayer, mediation, etc) do in fact engage the brain. Which is what we would expect as Christians. NT Wright says (“Mind, Spirit, Soul and Body: All for one and one for all reflections on Paul’s anthropology in his complex contexts (2011)):
God’s sphere and our sphere – are not thought of as detached or separate. They overlap and interlock. God is always at work in the world, and God is always at work in, and addressing, human beings, not only through one faculty such as the soul or spirit but through every fibre of our beings, not least our bodies. That is why I am not afraid that one day the neuroscientists might come up with a complete account of exactly which neurons fire under which circumstances, including that might indicate the person as responding to God and his love in worship, prayer and adoration. Why should the creator not relate to his creation in a thousand different ways? Why should brain, heart and body not all be wonderfully interrelated in so many ways that we need the rich language of mind, soul and spirit to begin to do justice to it all?
Overall, we know that there is more to religious experience than just brain activity, brain activity does not negate the existence of God, and that most importantly being a Christian is more than just religious experiences.
I hope this helped answer your question Jesse. Your question is a profound one with a lot of mystery attached. For more information I highly recommend either reading Sharon’s book or listening to her livestream on the 10th of Sept. Also, here is the link to the NT Wright article that I quoted: http://ntwrightpage.com/2016/07/12/mind-spirit-soul-and-body/
Please let me know if I can clarify anything or if I can answer any more of your questions.