Christmas Is the Greatest Mystery
It is the hour that split history in half.
Until that first Christmas, he had been, from eternity past, the
divine Son and second person of the Godhead. He was God’s glad
agent in creation (John 1:3; Colossians 1:16; Hebrews 1:2), and
from the beginning of time, he had upheld the universe at every
moment (Colossians 1:17; Hebrews 1:3).
But then came the great change — the blessed addition — at the very
heart of reality. The Word became flesh (John 1:14). God became
man. The Creator himself came as a creature, the Author entered
into his Story as a character. Without abandoning any of what it
means to be God, he took on all that it means to be human.
“This spectacular truth, at the center of what we celebrate at
Christmas, we call “the incarnation,” which means the “in-fleshing”
of the divine Son — God himself taking human flesh and blood and
all our humanness. Christmas is when he adds humanity to his
divinity, and does so that he might rescue us from our soul-
destroying rebellion, and lavish us with the everlasting enjoyment
for which we were made.
That Enigmatic Union
It is a glorious revelation, and it’s also a great mystery. This is
the greatest mystery in all of history, how God himself became
fully human without ceasing to be fully divine — that God, in all
his God-ness, united himself with all man-ness. Church history has
coined it “the hypostatic union,” the joining of two distinct
natures in one undivided person (“hypostatic” is just a fancy word
for “personal”). Jesus is fully God and fully man in one
And this union of God and man in Jesus is what makes possible our
own union with the Godhead through him. But the greatest mystery is
not how we are united to God by faith (through sheer grace and the
work of the Spirit), but how God united himself to us in the one
person of Christ.
“The union is so perfect,” says D.A. Carson, “that even though he
has two natures, he is only one person.” It is almost too good to
And so, “Jesus really does shoulder with us everything that it
means to be human,” adds Russell Moore.
He Really Is Human
When you ask Moore about the person of Christ, it’s Hebrews 2:11–
14, about Jesus’s humanness, that springs to mind.
“The humanity of Jesus is often the difficult thing to understand
for evangelicals,” he says. We’re quick to embrace Christ’s deity,
at least the orthodox among us. We’ve learned from day one that
Jesus is God. “We understand his deity. But also, he was a real and
genuine man, and is a real and genuine man.”
Moore rehearses “four fences” that come from the early church
councils and guard us from error when it comes to this great
Christmas mystery in the person of Christ: He is 1) fully God, 2)
fully man, 3) as one person in 4) two natures.
He “Emptied” Himself
One difficulty in this for the human mind is that we’re prone to
think of divinity and human in mutually exclusive terms. We might
speculate, If he “became man,” he must have ceased, in some sense,
to be God. Then we come across a text like Philippians 2:7, that he
“emptied himself,” and ask, Did he empty himself of attributes of
deity? Carson answers,
The expression is not what he emptied himself of; it’s an idiomatic
way of saying he became a nobody, he humbled himself completely,
not only to become a human being, but to go all the way to the
ignominy and shame and torture of the cross. . . . It’s talking
about the astonishing, unequal, unimaginable, indescribable, self-
humiliation in becoming human and then going so far not only to be
a slave, but a slave who dies on the cross.
The Mystery That Reveals: Three Lessons
The incarnation remains a great mystery, but Scripture does not
leave everything enigmatic. From our 17-minute interview with
Carson and 14 minutes with Moore, here are three important lessons
this otherwise mysterious doctrine reveals.
1. Divinity and humanity are not mutually exclusive.
“The two natures do not diminish each other,” says Carson. “He is
genuinely human, with all that means, and genuinely God, with all
that means, in two natures that maintain distinctness, even while,
at the same time, we insist that they are so united that he is but
one person. . . . It’s language like that that is needed to
preserve all the different contributing voices of the New Testament
to explain adequately, in summary form, what the Bible says about
Jesus as the God-man.”
And this lesson in the person of Christ, that full divinity and
full humanity are complementary, provides a glimpse into other
mind-bending, multi-dimensional realities as well, like the divine-
human authorship of Scripture, and the divine-human tension between
the sovereignty of God and the responsibility of man.
2. Humanity matters, as do our menial lives.
Moore mentions Jesus’s three decades as “a working-class day-
laborer in a completely-out-of-the-way place.” Year after year of
his quiet life, before launching into “public ministry,” serves a
remarkable affirmation and sanctification of our mundane and
And his becoming man also highlights the amazing value, privilege,
and dignity of humanity as God’s climactic creatures. Even above
angels. These “things that have now been announced to [us] through
those who preached the good news” are “things into which angels
long to look” (1 Peter 1:12). It is not an angel who now sits on
the throne of the universe, but a man (Hebrews 2:9). What amazing
grace that Jesus is “not ashamed to call us his brothers” (Hebrews
3. Jesus is the linchpin of prayer and worship.
In becoming man, he became for us the visible image of the
invisible God (Colossians 1:15). He is the radiance of his Father’s
glory (Hebrews 1:3). Our “light of the knowledge of the glory of
God” comes “in the face of Jesus Christ” (2 Corinthians 4:6), and
he is the singular “lamp” who will give the light of the glory of
God in a new creation with no need of sun or moon (Revelation
And so, says Moore, praying “in Jesus’s name” is no magical
incantation. “Jesus is the only human who has the right to approach
God.” Who may ascend the hill of the Lord? is the question of Psalm
24, and the ultimate answer is that Jesus is the only one who
utterly fulfills the vision, and only in him may we too ascend.
The greatest mystery of Christmas is also its greatest revelation.
“God has joined himself with us forever,” says Moore. “God has
identified eternally with us.”