How do we make sense of the idea that Christ is “fully God, fully human”?
I’ve wrestled with this question. And I’m guessing you have to.
As we enter Advent, I’m sorry to say we will not suddenly settle all the questions about what seminary grads may know as the hypostatic union—the combination of divine and human natures in the single person of Christ. Science does not have a whole lot to offer on the notion that someone can be both divine and human at the same time. But science does have a lot to say about the human side of things, even regarding the infant Jesus.
What does it mean to say that Jesus was fully human? I asked that of a number of scientists—like Justin Barrett and Mark McMinn—who worship Christ and study a range of aspects about human nature.
Barrett, McMinn, and others are partnering with us for a special Advent series in the coming weeks, in which we’ll reflect on God’s entry into the world, born of Mary, found in a manger, and, through his death on the cross, sharing fully in our human experience.
Fully and Uniquely
Much of the literature on faith and science considers the question of human uniqueness—what constitutes the image of God in us from a theological perspective, and what makes Homo sapiens distinctive in a scientific sense.
It is rich space, worthy of a series all of its own. But in seeking mere glimpses of what makes us uniquely human—for example, our ability to mimic distinguishes us from chimps—we may overlook that which makes us fully human. Perhaps it is our rational minds, our ability to be in relationship with one another and with God, or our duty as stewards of creation. Maybe it is creativity, symbolic behavior, our technological innovation, consciousness, free will, or the suite of skills, like language, that make us one of the most social and cooperative species to have walked the earth.
But what makes us fully human is also much more. It includes our genome, our incredibly complex brains with those enlarged cerebral cortexes, and even our microbiomes. It includes the way we procreate and nurture children through long and loving relationships (most of the time)—including the flow of neurochemicals like oxytocin as we bond with our parents.
We are fully human in the ways we learn—some things coming easier than others—and use language. To be fully human is to seek to know the thoughts of others, and yet be limited in certain ways by our own perspective, clouded by biases, and our inability to process all the information our senses bring in. It is to be formed by, participating in, and shaping culture.
To be fully human includes many things that are not uniquely human. All living things have stages of development—like our bruised knees when learning to walk, raging hormones of adolescence, leaving the nest, and, in some cases, creating a new one. There is menopause, wrinkles, and a decline in many abilities as we age. Sadly, at all stages, disease, pain, and ailments of all sorts are part of it—to be human is to have had a cold and a stomach bug, to have been depressed and anxious, to have survived trauma and suffered injury. Ultimately, it includes knowledge of and the experience of death. Again, these are not all unique to humans, but they are essential to a fully human existence.
To create things, to ask why questions, to wonder and to want to belong, to be confused and to need help, to consider right and wrong—I can keep going and going on what it means to be fully human. As a Christian, I also believe it includes a need for meaning and purpose. Whether that is a God-shaped hole set aside for the Christian God, or an existential impulse in pursuit of transcendence, we all seek out more than just the material things.
Science pursues many, if not all, of these topics. It contributes to our understanding of what makes us uniquely human as well as those aspects that make us fully human. And it is filled with disagreement; there is no scientific consensus on these questions about what makes us human. My lists above are merely suggestive, likely including items you would leave off—and excluding ones you would include.

- What does it mean to be human? Try this Science for Seminaries video.
- ORBITER has a nice series of content on what makes us unique.
- Want more video? Try this series on human uniqueness at Closer to Truth.
- Agustín Fuentes on race, aggression and sex, on creativity, and on Why We Believe.

- As we’ve previously suggested, maybe humans are created co-creators.
- Faraday Institute considers the human genome and imago Dei.
Theological Imagining
The hypostatic union captured my imagination in seminary, baffling me as I tried to wrap my head around it. I pursued it scientifically, theologically, and even poetically. How can anyone or anything be both fully human and fully divine?
Did baby Jesus depend on Mary for nourishment? Did he soil his swaddling cloth? And when he did, did he cry? Did the savior of the world really cry over such basic needs as food and a clean diaper? These questions troubled me. I could wrap my head around the fully human part. Or even the fully divine. But my head could never hold them both at once.
This series will pursue only the fully human part, but I invite you to wonder with me. As we learn together over the coming weeks new aspects of what it means to think of baby Jesus as fully human, what does it really mean for us to also say that Jesus was at the same time fully divine?
Ultimately, I believe it is a holy mystery. But I know firsthand how our theological imaginations can be enriched as we thoughtfully pursue such mysteries. So, please, join in this advent wonder.
Cheers,
Drew
