The Greatest Mystery Revealed

What child is this? This question, echoing through Christmas carols and nativity scenes, points to the greatest mystery ever revealed in human history. You see, when we look at that baby in Bethlehem, we’re not just looking at another human birth—we’re witnessing the moment when eternity entered time, when the infinite became finite, when God became man.

The apostle Paul calls this “the mystery of godliness: God was manifested in the flesh” (1 Timothy 3:16). For centuries, this truth was hidden, concealed in prophecies and shadows. But in the fullness of time, God revealed His ultimate plan: the eternal Word would take on human flesh to accomplish what no mere man could ever achieve.

Here’s the central truth we’ll explore today: Christ’s dual nature—fully God and fully man—uniquely qualifies Him as our perfect mediator and sympathetic high priest, giving us bold access to God’s throne of grace.

This isn’t merely theological speculation. This truth transforms how we approach God, how we understand our salvation, and how we live each day. The incarnation isn’t just a Christmas doctrine—it’s the foundation of our entire relationship with God.

The Problem That Required God to Become Man

But here’s the thing—why did God need to become man at all? What was the problem that required such a radical solution?

The writer of Hebrews gives us the answer: we needed a high priest who could “sympathize with our weaknesses” while being “holy, harmless, undefiled, separate from sinners” (Hebrews 4:15; 7:26). You see, humanity faced an impossible dilemma. We were fallen in Adam, standing under condemnation through one man’s disobedience. We were unredeemable by our own nature or effort.

The Infinite Chasm

Think about it this way: between holy God and sinful humanity lies an infinite chasm. God’s holiness is absolute, perfect, unchanging. Our sinfulness is total, affecting every part of our being. How could these two ever meet? How could sinful people approach a holy God without being consumed?

The Old Testament sacrificial system pointed to the answer but could never provide it. As Hebrews reminds us, “The law, having a shadow of the good things to come, and not the very image of the things, can never with these same sacrifices, which they offer continually year by year, make those who approach perfect” (Hebrews 10:1).

Prophetic Preparation

But God had a plan from the beginning. The prophet Isaiah declared, “Behold, the virgin shall conceive and bear a Son, and shall call His name Immanuel”—God with us (Isaiah 7:14). Later, he proclaimed that this child would be called “Wonderful, Counselor, Mighty God, Everlasting Father, Prince of Peace” (Isaiah 9:6).

What’s remarkable about these prophecies is how they hint at the mystery of the incarnation. This child would be born of a woman—fully human. Yet He would be called Mighty God—fully divine. His origins would be “from of old, from everlasting” (Micah 5:2), yet He would be born in Bethlehem at a specific moment in history.

The Necessity of the God-Man

You see, only a God-man could solve humanity’s dilemma. His divinity would possess infinite power to deal with infinite guilt. His humanity would qualify Him as our representative, able to stand in our place. As the early church father Athanasius wrote, “He became what we are that He might make us what He is.”

This wasn’t Plan B. This wasn’t God scrambling to fix a problem He didn’t anticipate. From before the foundation of the world, God planned that His Son would take on human nature to accomplish our redemption. The incarnation was the necessary means to our salvation.

The Perfect Solution – Christ’s Dual Nature

So how did God solve this impossible problem? Through the mystery of the incarnation—the eternal Word becoming flesh while remaining fully God.

Fully God: The Divine Nature

When John writes, “In the beginning was the Word, and the Word was with God, and the Word was God” (John 1:1), he’s establishing Christ’s eternal deity. This Word who became flesh possessed all the attributes of divinity—eternality, immutability, omnipotence, omniscience, omnipresence.

Paul confirms this in Colossians: “In Him dwells all the fullness of the Godhead bodily” (Colossians 2:9). Not part of God’s nature, not a diminished version of deity, but the complete fullness of divine essence dwelling in bodily form.

What’s interesting is that Christ’s divine nature qualified Him for aspects of salvation that no mere human could accomplish. Only God could bear infinite guilt. Only God could satisfy divine justice. Only God could conquer death and provide eternal life.

Fully Man: The Human Nature

But here’s where the mystery deepens. Paul tells us that Christ, “being in the form of God, did not consider it robbery to be equal with God, but made Himself of no reputation, taking the form of a bondservant, and coming in the likeness of men” (Philippians 2:6-7).

This is the kenosis—the self-emptying. But what did Christ empty Himself of? Not His divine nature, for that would make Him cease to be God. Rather, He voluntarily limited the use of His divine attributes, taking on the constraints of human existence.

He was born as a baby, grew in wisdom and stature, experienced hunger, thirst, fatigue, and temptation. He felt the full range of human emotions—joy, sorrow, anger, compassion. He lived a genuinely human life while never ceasing to be fully God.

The Hypostatic Union

Theologians call this the hypostatic union—two complete natures, divine and human, united in one person without confusion, change, division, or separation. This wasn’t a temporary arrangement. When the Word became flesh, it was permanent. Christ remains the God-man forever.

This union enables Christ to serve as the perfect mediator. As Paul writes, “There is one God and one Mediator between God and men, the Man Christ Jesus” (1 Timothy 2:5). Notice he calls Him “the Man Christ Jesus”—emphasizing His humanity—while affirming His unique role as the one Mediator, which requires His deity.

The Virgin Birth: Preserving Both Natures

The virgin birth wasn’t just a miraculous sign—it was theologically necessary. Through Mary’s humanity, Christ received genuine human nature. Through the Holy Spirit’s conception, He avoided the transmission of original sin and maintained His divine nature. The virgin birth preserved both natures in their integrity.

Matthew emphasizes this when he quotes Isaiah’s prophecy: “Behold, the virgin shall be with child, and bear a Son, and they shall call His name Immanuel, which is translated, ‘God with us'” (Matthew 1:23). God with us—not God instead of us, not God above us, but God with us in our humanity.

The Kenosis: Self-Limitation, Not Self-Emptying

So what does it mean that Christ “emptied Himself”? The Greek word kenosis doesn’t mean He laid aside His divine attributes—that would be impossible since God is immutable. Rather, He voluntarily limited their use, choosing not to exercise His divine prerogatives for His own benefit.

He who created the universe allowed Himself to be born in a stable. He who sustains all things by the word of His power experienced human weakness. He who knows all things grew in wisdom. He who is life itself died on a cross.

This self-limitation was voluntary and purposeful. It enabled Him to live a genuinely human life while remaining fully God. It qualified Him to be our sympathetic high priest while maintaining His divine power to save.

The Eternal Benefits – Our Bold Access

Now, here’s where this theology becomes intensely practical. Because of Christ’s dual nature, we have benefits that no other religion or philosophy can offer.

An Eternal High Priest

The writer of Hebrews contrasts Christ’s priesthood with the Levitical system: “The former priests, on the one hand, existed in greater numbers because they were prevented by death from continuing, but Jesus, on the other hand, because He continues forever, holds His priesthood permanently” (Hebrews 7:23-24).

You see, the Levitical priests died. Each one required a successor. The system was built on mortality and replacement. But Christ lives forever. His priesthood cannot pass to another because He never dies. He is “able to save to the uttermost those who come to God through Him, since He always lives to make intercession for them” (Hebrews 7:25).

A Perfect Sacrifice

The Levitical priests offered sacrifices repeatedly because their sacrifices were insufficient. The very repetition proved their inadequacy. But Christ “offered Himself once for all” (Hebrews 10:10). His sacrifice was complete, sufficient, eternal.

Why? Because of His dual nature. As man, He could die in our place. As God, His sacrifice possessed infinite value. One sacrifice, offered by the God-man, accomplished what millions of animal sacrifices could never achieve.

A Sympathetic Advocate

But here’s what makes this even more amazing. Hebrews tells us, “We do not have a High Priest who cannot sympathize with our weaknesses, but was in all points tempted as we are, yet without sin” (Hebrews 4:15).

Christ’s humanity enables His sympathy. He knows what it’s like to be tired, hungry, rejected, misunderstood. He faced every category of temptation we face—the lust of the flesh, the lust of the eyes, and the pride of life—yet He never sinned. He understands our struggles from the inside.

At the same time, His deity ensures His power to help. He’s not just a sympathetic friend who feels bad for us. He’s the almighty God who can actually do something about our situation.

Bold Access to the Throne

This brings us to the climax: “Let us therefore come boldly to the throne of grace, that we may obtain mercy and find grace to help in time of need” (Hebrews 4:16).

Think about what this means. The throne of grace is God’s throne—the seat of ultimate authority in the universe. Under the old covenant, only the high priest could approach God’s presence, and only once a year, with blood, in fear and trembling.

But because of Christ’s incarnation and sacrifice, we can come boldly. Not arrogantly, but with confidence. Not presumptuously, but with assurance. We can approach the throne of the universe knowing we’ll find mercy and grace.

Present Intercession

And here’s something many Christians don’t fully grasp: Christ’s work for us isn’t finished. He’s not just sitting passively in heaven. He’s actively interceding for us right now. Romans 8:34 tells us that Christ “is even at the right hand of God, who also makes intercession for us.”

When you’re struggling with sin, Christ is praying for you. When you’re facing trials, Christ is interceding for you. When you feel weak and inadequate, Christ is pleading your cause before the Father. His intercession is based on His perfect sacrifice and His sympathetic understanding of your humanity.

Living in Light of the Incarnation

So what does this mean for how we live each day?

Confidence in Prayer

First, it transforms our prayer life. We don’t approach God hoping He might listen. We come boldly, knowing that our High Priest has opened the way. We can bring our deepest struggles, our greatest fears, our most persistent sins, knowing we’ll find mercy and grace.

Comfort in Suffering

Second, it provides comfort in suffering. When life is hard, when you feel alone, when circumstances overwhelm you, remember: your High Priest understands. He’s been where you are. He knows what you’re going through. And He has the power to help.

Assurance of Salvation

Third, it gives us unshakeable assurance. Your salvation doesn’t depend on your performance but on Christ’s perfect work. He who knew no sin became sin for you. He who was rich became poor for your sake. His sacrifice was sufficient, His intercession is constant, His love is unchanging.

Motivation for Holiness

Finally, it motivates us toward holiness. Not to earn God’s favor—we already have that in Christ. But because we’ve been loved so completely, forgiven so freely, accepted so fully. The incarnation shows us the lengths to which God went to save us. How can we not respond with grateful obedience?

The mystery is revealed: God became man that man might become the children of God. In the incarnation, heaven and earth meet, divinity and humanity unite, and the love of God is perfectly displayed.

What child is this? He is the Word made flesh, full of grace and truth. He is our sympathetic High Priest, our perfect sacrifice, our eternal advocate. He is Jesus Christ, the same yesterday, today, and forever. He is our Lord and our God, worthy of all worship, honor, and praise.

Because of the incarnation, we can approach God’s throne with confidence, knowing we’ll find mercy and grace to help in our time of need. This is the gospel. This is our hope. This is the mystery of godliness: God was manifested in the flesh for us and for our salvation.