Westminster Project 8.2

The Son of God, the second person in the Trinity, being truly and eternally God, of one substance and equal with the Father, when the fullness of time came, took upon himself mankind’s nature, with all the essential properties and common infirmities of it, yet without sin, being conceived by the power of the Holy Spirit in the womb of the virgin Mary, and of her substance. Thus two whole, perfect, and distinct natures, the Godhead and the manhood, were inseparably joined together in one person, without conversion, composition, or confusion. This person is truly God and truly man, and yet is one Christ, the only mediator between God and man.
(WCF 8.2)

Over the past couple of weeks, we’ve been studying Chapter 8 of the Westminster Confession of Faith (WCF), which focuses on a particular office—that of the Mediator. WCF 8.1 plainly states that humanity, being sinful, needs a mediator—someone to stand between us and Almighty God—and that this mediator is Jesus Christ. This week, the confession turns our attention to the question: who exactly is Jesus Christ?

We begin with His eternal nature. Jesus is the Son of God, the second person of the Trinity, truly and eternally God—of one substance and equal in glory with the Father. Drawing on passages such as John 1:1,14; 1 John 5:20; Philippians 2:6; and Galatians 4:4, as well as the language of the Nicene Fathers, we are immediately reminded that God’s chosen mediator is none other than His own Son. But here’s the key: His sonship does not make Him any less divine than the Father. Rather, He is of the same essence and equal in glory.

Let’s pause to consider what this means. The Son is not the Father, and the Father is not the Son—yet both are fully and properly God. This is why the language of "substance" and "person" is so helpful. God is one in substance but not in person. There are three distinct persons in the Godhead—what we call the Trinity: one God in three Persons. Much more could be said here, but what is vital to grasp is this: the mediator that God ordained (WCF 8.1) is none other than the eternal Son of God.

So how did He come to take on this role? The confession explains that, when the fullness of time had come, He took upon Himself human nature—with all its essential properties and common infirmities, yet without sin. He was conceived by the power of the Holy Spirit in the womb of the Virgin Mary and of her substance. In other words, the third person of the Trinity (the Spirit) miraculously conceived Jesus of Nazareth in Mary’s human body (Luke 1:27, 31–35; Galatians 4:4). This is what we call the doctrine of the Incarnation—whereby the Spirit joined the divine nature with human nature. This is where the Nicene Creed’s phrase comes from: Jesus is “very God and very man.”

Are we expected to fully comprehend this? No. As the 4th-century theologian Augustine once quipped: “Deny the Trinity and you lose your soul; try to understand the Trinity and you lose your mind.”

This is truly a mystery. Yet the central point is clear: from eternity past, God did not plan for sinful mediators to stand between Himself and us, but rather for His own Son to do so—once and for all. Because God became truly human in Jesus—yet remained sinless—He can stand as our eternal and merciful mediator. He draws us toward God’s holiness while fully knowing our human experience (Hebrews 2:14–17; 4:15).

As the confession beautifully summarizes:
“Thus, two whole, perfect, and distinct natures—the Godhead and the manhood—were inseparably joined together in one person, without conversion, composition, or confusion. This person is truly God and truly man, yet one Christ—the only mediator between God and man.”
We have a God who, from eternity past, purposed to have a real and restored relationship with us. Though we are sinful and He is Almighty, He made a way for reconciliation through His Son, Jesus Christ—Immanuel, God with us.