Acetylcholine (ACh), dopamine (DA), serotonin (5-HT), γ-aminobutyric acid (GABA), and glutamate (Glu) form the core chemical language of the brain. ACh enables muscle contraction, attention, and memory (revealed by Otto Loewi’s 1921 “Vagusstoff” experiment and Henry Dale’s pharmacology). DA shapes motivation, reward, and movement (established as a neurotransmitter by Arvid Carlsson in the 1950s, transforming our understanding of Parkinson’s disease). 5-HT modulates mood, sleep, and social behaviour (isolated and named by Maurice Rapport, Arda Green, and Irvine Page in 1948). GABA provides the brain’s primary inhibitory balance (independently identified as a brain metabolite and transmitter by Eugene Roberts and Jorge Awapara in 1950). Glu drives excitation, learning, and plasticity (recognized through mid-20th-century work by David Curtis and John Watkins). From a Christian perspective, this intricate neurochemical harmony reflects the ordered creativity of God (“fearfully and wonderfully made” Psalm 139:14), and invites stewardship of mind and body as temples of the Holy Spirit (1 Corinthians 6:19), where renewing the mind (Romans 12:2) and cultivating virtues like self-control and peace (Galatians 5:22–23) align biological insight with spiritual formation. Practically, this science undergirds treatments for depression, anxiety, addiction, epilepsy, and neurodegeneration, empowering personal wellbeing through informed care while strengthening societal health by reducing stigma, guiding ethical medicine, and fostering compassion for mental illness as both a biological and moral concern.