The virgin birth of Jesus is one of the most important, if not unbelievable, aspects of the nativity story. 

This belief in the supernatural conception of Christ has been enshrined in the ecumenical creeds, which date back to the earliest centuries of the church, and stems from the biblical nativity account as described in Matthew 1:18-25 and Luke 1:26-38.

This idea is so important, in fact, that the Catholic tradition maintains a doctrine referred to as the perpetual virginity of Mary, which claims that Jesus’ mother remained a virgin for the entirety of her life. This doctrine is closely associated with the idea that if Jesus was sinless, then by proxy, Mary was sinless as well. 

However, this belief contradicts both the biblical account of Mary’s life and its description of sex. 

For example, Jesus had at least six other siblings, including two brothers who authored letters found in the New Testament. Jesus mentions his mothers and brothers in Matthew 12:46-50, and his brothers are called out by name (James, Joses, Judah, and Simon) in Mark 6:3. It is referenced in Matthew 12:50 that Jesus had sisters (plural), though we don’t know exactly how many of them there were or their names. 

If Mary and Joseph never consummated their marriage and these children were all born of a virgin, this raises serious questions about the nature of their humanity, whether they would possess the same divinity as did Jesus, as well as what all this means for the doctrine of the Trinity. It also raises questions about the nature of Mary herself, and the circumstances of her own conception.

The more simple and likely answer is that although Jesus was born while Mary was still a virgin betrothed to Joseph, his younger (half) siblings were born like any other children, with Joseph as their natural father. 

Furthermore, adherence to the doctrine of Mary’s perpetual virginity also betrays an unbiblical understanding of sex that sees sexuality as inextricably connected to sinfulness. However, sex was created by God himself before sin entered the world, not only as a means of procreation but as a covenantal act of marriage. 

Throughout scripture, we are given myriad commandments and warnings about not using and abusing sex outside the confines of a lifelong marriage commitment between one man and one woman. But that is reflective of the fact that humans so often get sex wrong, not that sex itself is wrong. 

But if Jesus’ virgin birth was not necessary on account of the inherent sinfulness of sex, why was it necessary?

Jesus as the New Adam

While the necessity of the virgin birth isn’t owing to the sinfulness of sex, sin is an essential part of the equation. 

As Paul teaches in numerous places in his letters, when Adam and Eve sinned, something fundamentally changed about who they were. While they were created in the image of God, and humanity continued to bear God’s image even amid sin, we have fallen from our previous state of harmony with God and have continued in that state in every successive generation. 

As a result, all of humanity is born separated from God, both from a positional standpoint through our descendancy from Adam and from the inherited predisposition we have from birth toward sinfulness. 

This is what theologians refer to as the doctrine of total depravity, which can be described as a state of complete fallenness that all humans inherit and that keeps us separated from God. As a result of this sin nature, we are unable to reconnect to God, and there is no amount of good works we could do that could change our nature or cancel out our sin.

As Paul says in Romans 3:10-12, “None is righteous, no, not one; no one understands; no one seeks for God. All have turned aside; together they have become worthless; no one does good, not even one.”

So our separation from God is not only a result of our individual sin but also our fundamental connection with the sinful Adam. Therefore, “in Adam, all die” (1 Corinthians 15:22). Were Jesus born of an earthly man and woman, he would be an imperfect savior, and thereby no savior at all. 

However, because Jesus is not a natural man, but a God-man who possesses two natures in his one person, when we come under his headship, the millennia long cycle of sin and death is finally broken.

Paul puts it this way in Romans 5. 

Therefore, just as sin came into the world through one man, and death through sin, and so death spread to all men because all sinned…For if, because of one man’s trespass, death reigned through that one man, much more will those who receive the abundance of grace and the free gift of righteousness reign in life through the one man Jesus Christ. Therefore, as one trespass led to condemnation for all men, so one act of righteousness leads to justification and life for all men. (Romans 5:12, 17-18)

But this only works if Jesus truly was the only righteous man to walk the earth since Adam’s pre-sin state. And that couldn’t happen if Jesus were a descendent of Adam. Instead, he needed to be a replacement for Adam.

And that’s exactly what happened. Jesus constitutes a new humanity—the type of humanity God always intended for us to have. 

RELATED: Why I Don’t Think Jesus Was Born in a Stable (And Why It Matters)

Jesus as the Substitute and Mediator

Nevertheless, the incarnation was not itself a sufficient work for our salvation. In order for us to experience eternal life in Jesus, all of our sin needed to be removed from us, and Jesus would need to conquer not only sin but death itself. 

This is what Jesus did when he sacrificially died on the Cross and rose again to new life. In so doing, through a great mystery of God, Jesus paid the price for sin that only God could but only humanity should. 

Canceling our debt of sin by virtue of his death and becoming the firstfruit of our spiritual resurrection and physical restoration by virtue of his physical resurrection and glorification, Jesus, the God-man born of humanity and divinity, paved the only way for humanity to reconnect with God, the giver of life, both in the immediate and for eternity. 

So now, if we confess our sin and place our trust in Jesus, all of our sin is put on him, and all of his righteousness is given to us. This is what theologians refer to as “double imputation.” 

Paul puts it this way in his second letter to the church in Corinth. 

For our sake he made him to be sin who knew no sin, so that in him we might become the righteousness of God. (2 Corinthians 5:21)

This is made possible not by some type of legal erasure but by virtue of the fact that when we place our faith in Jesus, it isn’t just that we become followers of Jesus, but rather our very life is “hidden with Christ in God” (Colossians 3:3).

This is why the phrase Paul most often uses to refer to Christians is those who are “in Christ.” While we don’t become gods ourselves, we do “become partakers of the divine nature” (2 Peter 1:4) through our connection with Jesus, who identified with us in our humanity.

The only way for that to be possible would be if Jesus is both fully human and fully God. In other words, he had to be born of a virgin, miraculously conceived by the Holy Spirit.

This is a lot to take in. If I’m being honest, the longer I study and contemplate it, the more I feel as though I will never really grasp it. And yet it is still a fundamental reality of our salvation that is only possible if the virgin birth is true. 

And since it is true, we possess “the riches of the glory of this mystery, which is Christ in you, the hope of glory” (Colossians 1:27). 

An Addendum: Why Should We Believe in the Virgin Birth?

While the doctrine of the virgin birth is as beautiful as it is mysterious, what remains in question for many is whether it actually happened. And, unfortunately, there is no archeological or scientific discovery that could ever answer that question definitively. 

Nevertheless, that doesn’t mean that we have no reason to believe in it, even if it requires a measure of faith. 

The reason I say that is simple. I believe Jesus truly rose from the dead. And in the words of Andy Stanley, “If a man can predict his own death and resurrection, and pull it off, I just go with whatever that man says.”

But how can we know that Jesus really rose from the dead? I talk about that at length here. 

For Further Reading

If you found this article helpful and would like more resources, check out these classic works. 

• Cur Deus Homo? by Anselm of Canterbury
• On the Incarnation of the Word by Athanasius of Alexandria

Or these modern ones.

• Person of Christ by Donald Macleod
• One with Christ: An Evangelical Theology of Salvation by Marcus Peter Johnson