The Physiology of Fear and the Faith that Fights It

“Be still, and know that I am God.” (Ps. 46:10)

There is a resounding call to stillness throughout the Bible. Whether exemplified through Daniel’s consistent prayer and petition (Daniel 6:10) or through Paul’s direct admonition to “not be anxious about anything, but in every situation, by prayer and petition, with thanksgiving, present your requests to God” (Phil. 4:6), the life of a follower of Christ is one of offsetting the chaos of a broken world with the peace of a sovereign God. It is the only way to thrive in an existence that seeks to deprive us of the lasting joy God desires for His children by stealing, killing, and destroying.

While these are not new topics, and many before me have discussed prayer, stillness, and meditation, I would like to approach this conversation from a different perspective. In our soul pursuit of a spiritual God, it is easy to forget we are embodied souls. A common critique of faith-based responses to anxiety is the stereotype of an ill-equipped pastor telling a depressed and anxious teen to simply pray it away. While this can be an oversimplification, the prescription of Philippians 4 remains true: prayer and petition are central to combating anxiety. But why is that? Why is prayer a viable strategy to combat the viciousness of crippling anxiety? Let’s seek to answer that question from both theological and physiological perspectives.

According to Yale Medicine, anxiety is a mental health state or condition “characterized by excessive worry, fear, or apprehension.” Fear is the key word here. This is where we build both our theology and physiology. Let’s begin.

Fear is descriptive of the body’s natural ability to detect threats. Fear in and of itself is not bad. Get that through your head—fear is not bad. Fear is the emotional response to a perceived threat, triggering a cascade of biological and psychological processes. This can result in feats of strength never trained for (think of a mother lifting a car off her child), endurance never built (outrunning a bear or, for Jurassic Park fans, a Velociraptor in a commercial kitchen), and power never practiced (Neo jumping from one building to another in The Matrix, an exaggerated yet conceptually fitting example considering belief plays a role in perceived limitations). These transient superpowers are physiologically a byproduct of fear.

Fear is processed in the brain by the amygdala, which sorts incoming information. It determines whether a noise in the living room is an intruder or just the ice maker. If the amygdala deems the input potentially threatening, it signals the duty captain—the hypothalamus—to initiate a stress response.

There are two pathways through which the hypothalamus sends signals:

  1. The Sympathomedullary (SAM) Pathway – This fast-acting pathway releases adrenaline and norepinephrine into the bloodstream, leading to increased heart rate, respiratory rate, and sweaty palms—the immediate fight-or-flight response.
  2. The HPA Axis (Hypothalamic-Pituitary-Adrenal Axis) – When stress is prolonged, the hypothalamus releases Corticotropin Releasing Factor (CRF), which signals the pituitary gland to release Adrenocorticotropic Hormone (ACTH). ACTH then prompts the adrenal glands to release that hormone we all love to hate - cortisol, the body’s long-term stress hormone.

Cortisol, I might add, gets a bad wrap. While most think of it with the same disdain as the likes of Cruella Devil, cortisol is actually a superpower hormone when gauged properly. Let’s hype up this vilified hormone a bit. Cortisol is one of the body’s natural stimulants. It increases alertness and energy availability. It increases a process called gluconeogenesis which is the conversion of proteins and fats stored in the body to glucose, the energy currency of the body. It regulates blood sugar to ensure a well-regulated and steady supply of energy. It acts as an anti-inflammatory in order to prevent overreactions of the immune system responses. It maintains blood pressure by acting as a regulator for hormones that are involved in blood circulation. It actually can enhance your focus and memory via that very heightened state of the senses. Cortisol peaks in the morning, following the natural circadian rhythm of our day, helping us feel awake and ready to take on the day.

However, prolonged exposure to cortisol due to chronic stress can lead to serious health issues, including:

  • Hypertension
  • Heart disease
  • Anxiety and depression
  • Chronic pain
  • Insomnia
  • Metabolic disorders
  • Autoimmune conditions

This sounds like a lot of doom and gloom. And frankly, it is! Cortisol is both empowering and terrorizing. Many of our modern day diseases are a byproduct of this chronic exposure to cortisol. The problem is not fear, stress, or even cortisol itself—it is the chronic exposure to cortisol. This begs the question: How do we regulate our stress responses so that they strengthen us rather than break us?

Our amygdala often misinterprets threats. The brain does not always differentiate between a real danger and a perceived one. At some level your brain doesn’t care if the scary shadow is actually a monster or your shih tzu, either way, you’re gonna get scared and the body is going to respond. The differentiator is whether or not that response is allowed to continue or not. In order for the command center to order a cease fire of hormonal activity, you have to see and perceive clearly the reality of the threat before you. Is this a real threat to me or is this a matter of misperception? The only way of answering this question is through the active signalling of the brain’s voice of reason – the prefrontal cortex, the source of rationality in the brain. When the prefrontal cortex steps in it is able to evaluate a situation and determine whether or not this threat response is warranted, and if it is not, it inhibits the amygdala’s response consequently putting a cap on the unnecessary release of cortisol.

But this doesn’t explain why so many of us, despite living relatively safe lives– free from wild animals or active war-zones–still struggle with chronic stress and anxiety. That is where I would pose the question: how well do we examine the realities of what we deem threatening? I would vie to say that most of us struggle to view reality apart from the lens of distortion that comes from the nature of our upbringing, trauma’s, and lies we have repeatedly chosen to believe. These are what lead us to only seeing the shadow and never the shih tzu. Our problem is most often not that we face an unprecedented level of threats to which our bodies must overproduce cortisol, but that we view our threats as being far greater than they actually are. By that I mean to say that public speaking, job interviews, deadlines, and due bills are never life threatening. Because of that, by way of rationality, we should not perceive them as such. Yet, for some reason we do. Again. And again. And again. The result? Chronic stress, anxiety and the conditions that coincide with it.

Paul tells us that the antidote to anxiousness is prayer and thanksgiving. Why? Because prayer puts things into perspective. Distorted fear is only possible when lacking a reference point. If someone showed you a picture that made me look seven feet tall, you would either believe it or deny it based on prior knowledge of my actual height. Similarly, prayer aligns our perspective with God’s, allowing us to see our fears in proper proportion.

Jesus tells us that we need not fear anything—not even death. A rightly ordered fear of God leads to rightly ordered physiological responses. When we fear God alone, we obey His commands and put earthly threats in their rightful place.

By God’s grace, we have physiological systems that enable us to respond to threats with energy and strength. However, we are not meant to live in constant fear-driven reactivity. Our theological framework for managing fear is prayer and thanksgiving, allowing us to see clearly with both our prefrontal cortex and our souls.

None of this is to say that there are not a plethora of graces that God has given us to aid in the problem of chronically raised levels of cortisol due to stress and anxiety. All means available to you should be leveraged as an aid in bringing the perceived threats of our world down to their size relative to God’s power revealed through Christ in resurrecting from the dead. Here is a short list of strategies that are viable means of treating and managing the physiological effects of elevated cortisol.

  • Counseling – Processing fears with a trained professional can help reframe distorted perceptions.
  • Exercise – Physical activity reduces anxiety symptoms by 60% and conditions the body to handle stress.
  • Breathing Techniques – Breath control influences the nervous system, shifting us from fight-or-flight to rest-and-digest mode.
    • Try this: Breathe in through the nose for 3 seconds, inhale again, then exhale through the mouth for 4-6 seconds.
  • Supplementation – Certain natural supplements can support stress resilience:
    • PS100 (Phosphatidylserine) – Helps regulate cortisol and supports cognitive function.
    • Just Calm (Bifidobacterium longum 1714™) – A probiotic strain that reduces cortisol levels and enhances emotional regulation.
    • Exogenous Ketones – Provide an alternative energy source for the brain, reducing neuroinflammation and stabilizing mood.

We are not meant to live enslaved to fear or the physiological consequences of chronic stress. God, in His wisdom, has designed our bodies with the capacity to respond to threats in a way that protects and strengthens us. But He has also given us the means to discern when that response is no longer needed.

The call to “be still and know that I am God” is not an empty platitude. It is a practical invitation to reorient our perception, to place our fears before the Almighty, and to recognize that our ultimate security is in Him. When we do this, we train our minds and bodies to respond to stress in a way that brings peace rather than destruction.

In a world that constantly tells us to hustle, worry, and control, God calls us to stillness. And in that stillness, we find freedom.