Few experiences are more wonderful than holding a newborn. Your heart melts with loving wonder. “You’re so beautiful. Just perfect!” Even amidst that gentle marveling, fierce-protective instincts arise. “I would give my life for you against all comers.”

How much more so for Mary as she held Jesus. In his well-loved Christmas song, Mark Lowery asks, “Mary, did you know . . . when you kiss your little baby, you’ve kissed the face of God?” Though she would have to ponder the depths of it all her days, the angel had indeed told her, “The child to be born to you will be called holy, the Son of God” (Luke 1:35).

This is one of the first and greatest titles given to Jesus. But what does it mean? “Son of God” comes layered with meaning.

Human, Hebrew, King

In giving Jesus’s genealogy, Luke tells us that Adam was the “son of God” (Luke 3:38). He was uniquely created, but he was also the father of the human race. So there’s a sense in which we are all sons of God. Paul affirms this universal sonship by quoting a Greek poet: “We are indeed his offspring” (Acts 17:28).

But Scripture gives us another sense in which the chosen and called people are collectively God’s son. “This is what the Lord says: Israel is my firstborn son” (Exodus 4:22). God birthed his people in redeeming them from slavery in Egypt. Centuries later, beginning with David, the kings of Israel were considered to be the sons of God. This was a sonship by divine anointing that led to a special intimacy: “He shall cry to me, ‘You are my Father, my God, and the Rock of my salvation.’ And I will make him the firstborn, the highest of the kings of the earth” (Psalm 89:26–27).

Jesus fulfilled all three of those biblical meanings of “son of God.” (1) He was born of Mary and so was (and is) truly human, a descendent of Adam and Eve, one of the image-bearing offspring of God, just like any of us. (2) Jesus was also truly a Hebrew. Luke reminds us that he was circumcised on the eighth day (Luke 2:21), marked as part of Israel, the son of God. But more, Jesus was the first of the new Israel, the founder of a people redeemed by grace and joined to him through faith. (3) Jesus was a descendent of David, and hailed as the true heir to David’s throne (Luke 1:32). Anointed by the Holy Spirit at his baptism, Jesus is the Christ, the son of God who is the everlasting king of his people.

Eternal Son in Skin and Time

However, a deeper, older, more profound sense emerges in which Jesus is the unique Son of God. Thanks to John’s Gospel, we have the privilege of overhearing Jesus’s personal prayers to his heavenly Father shortly before his arrest. We learn the extent of this intimacy between them.

Father, I desire that they also, [the people] whom you have given me, may be with me where I am, to see my glory that you have given me because you loved me before the foundation of the world. (John 17:24)

The relationship between the Father and the Son is eternal. Before the creation of anything, the Father loved the Son and the Son loved the Father — all in the personal, flowing bonds of love, the communion of the Holy Spirit. Though this mystery bends our minds, we glean that relationship is at the very heart of the being of the triune God. The child in Mary’s arms was the eternal Son of God taking up our humanity in the particular person Jesus. He has been the divine Son of God forever, and now is Son of God in skin and in time.

“Before the creation of anything, the Father loved the Son and the Son loved the Father.”

In Matthew’s Gospel, Jesus pulls back the curtain on this deep mystery and gives us a peek into eternity when he declares, “No one knows the Son except the Father, and no one knows the Father except the Son and anyone to whom the Son chooses to reveal him” (Matthew 11:27). Knowing is more than factual knowledge; this knowing is relational intimacy. It includes a continuing exchange of love between Father and Son (again, in the Spirit).

Father and Son are so close that no one and nothing can get between them. This relationship precedes all things. This knowing is the foundation of the central Christian affirmation, “God is love” (1 John 4:7). In Jesus, we witness the relationship that undergirds all creation appear before our eyes in particular flesh, blood, posture, and vocal tenor.

Sons in the Son

The marvel deepens when we realize that the incarnation means God is opening up this utterly unique relationship to include us. This passage from Paul makes for a fabulous Christmas text:

When the fullness of time had come, God sent forth his Son, born of woman, born under the law, to redeem those who were under the law, so that we might receive adoption as sons. And because you are sons, God has sent the Spirit of his Son into our hearts, crying, “Abba! Father!” So you are no longer a slave, but a son, and if a son, then an heir through God. (Galatians 4:4–7)

“The triune God desires to adopt us into his eternal relationship of love.”

In Christ, the triune God adopts us into his eternal relationship of love. He makes this possible not only legally, through the forensics of atonement, but experientially, through the sending of the Spirit of his Son. The eternal Son brought his relationship with his Father among us in the incarnation. Now that he has returned to heaven, he brings us into his relationship with his Father by the gift of his own Spirit within us. We don’t just get information about redemption. We cry out as the Spirit vocalizes within us, “Abba! Father!”

All believers — whether men, women, boys, or girls — are sons of God in being joined to the one eternal and incarnate Son of God, Jesus.

Fellowship with Father and Son

We may well wonder if we truly are to be included in such love. Am I one of those “to whom the Son chooses to reveal him”? What a comfort then, to read the very next words out of Jesus’s mouth: “Come to me, all who labor and are heavy laden, and I will give you rest” (Matthew 11:28). Jesus wants us in on his relationship with the Father.

In his first letter, John says that he writes so that his readers “may have fellowship with us.” Then, he explains what that means: “Indeed our fellowship is with the Father and with his Son Jesus Christ” (1 John 1:3). Jesus is uniquely Son of God in a way no mere human, nation, or king ever could be. Yet he desires to share that sonship with us, that we might be taken into the very life of Father, Son, and Holy Spirit.

And at Christmas, of all times, this mystery, now revealed, resounds in our hearts,

Silent night, holy night,
Son of God, love’s pure light.
Radiant beams from thy holy face
With the dawn of redeeming grace,
Jesus, Lord at thy birth.
Jesus, Lord at thy birth.