Knowing God and the Life He Shares (John 17:1-4)

Introduction

Before being hired here at Cornerstone, I attended Cedarville University, where I studied Worship Ministry and Music. During my senior year, I had room in my schedule for an elective and decided—along with my roommate Stuart—to take Christian Theology II, a course focused on Christology and Pneumatology. That class changed the trajectory of my ministry.

I had already taken Theology I, but this course pushed much deeper. In particular, when we began studying the doctrine of the Trinity, I realized how limited my understanding of God actually was. My professor, Dr. Marsh, walked us carefully through Scripture and church history, and I remember leaving one class especially confused—my brain completely scrambled. I spent hours that night rereading notes and textbooks, trying to make sense of it.

But as the course continued, things began to click. And I can honestly say this: understanding God as Trinity reshaped my understanding of salvation. It was no longer just about forgiveness or future hope—it became about participation in the life God already possesses. That realization was breathtaking.

That experience is part of why I care so deeply about teaching theology—not as abstract ideas, but as truths that help us read Scripture clearly and know God rightly. Tonight, I want to do something a little different. Instead of starting with the doctrine of the Trinity, I want to end with it. I want to show you how Scripture itself—specifically John 17—leads us there. My goal is to let the Bible do the work, and then to explain the doctrine that becomes unavoidable if we take the text seriously. The Trinity is not something Christians invented to be clever. It is the only way to speak faithfully about the God Jesus reveals. So, turn with me to John 17, where we’ll read the first five verses of what’s often called Jesus’ High Priestly Prayer.

Big Idea: Eternal life is knowing God, and knowing God means being invited into the eternal life God already shares as Father, Son, and Spirit.

1. Eternal Life is Knowing God (v. 3)

In verse 3, Jesus gives us one of the clearest definitions of eternal life in all of Scripture. What’s interesting is that He doesn’t describe the effects of eternal life—He defines it. According to Jesus, eternal life is not primarily about living forever, and it’s not primarily about heaven. Eternal life is relationship. It is knowing God.

But what does Jesus mean when He talks about knowing God? In the Bible, “knowing” involves more than information. It includes personal relationship, shared life, and covenant faithfulness—being bound to someone in love and loyalty. Hosea 6:6 says that God desires “steadfast love and not sacrifice, the knowledge of God rather than burnt offerings.” Knowing God is more than knowing about God; it is relational at its core.

There is also a deeply encouraging implication in Jesus’ definition: eternal life begins at salvation. If eternal life is knowing God—relationally, not merely intellectually—then eternal life is a present reality, not only a future hope. That doesn’t mean you won’t die someday. It means that your relationship with God—what Jesus calls eternal life—has already begun and will never end. If eternal life is knowing God, the next question is unavoidable: How can God be known at all?

2. God is Known Only Because He Makes Himself Known (vv. 2-3)

This is a foundational truth with massive implications, and verse 2 makes it unmistakably clear: knowledge of God is a gift, not a human achievement. The repeated language of giving is intentional. The Father gives authority. He gives people. He gives eternal life. The point is simple but profound—God must act first for relationship to exist. We do not find God; God makes Himself known.

Jesus says this explicitly elsewhere. In Matthew 11:27, He says, “All things have been handed over to me by my Father, and 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.” Knowledge of God is not the result of effort, intelligence, or sincerity—it is the result of revelation. Without God acting first, we would not know Him at all.

What’s remarkable is how this truth intersects directly with what Jesus says in verse 3. Eternal life requires knowing both the Father and Jesus Christ whom He has sent. That means Jesus is not an optional addition to knowing God—He is the means by which God is known. We cannot separate God from Christ and still claim to know Him. To know Jesus is to know God.

Verse 2 reinforces this again when Jesus acknowledges that the Father has given Him authority over all flesh to give eternal life to those the Father has given Him. Eternal life—defined as knowing God—is given through Christ. It comes to those who trust in His saving work, by His authority and power.

So if God reveals Himself through Jesus, the next question naturally follows: what does that revelation actually look like in history?

3. God’s Glory is Revealed Through the Obedient Mission of Jesus (John 17:1, 4)

Jesus now refers to “the hour,” which throughout John’s Gospel points to the cross. By this point in the story, we know that the glory Jesus receives from the Father does not bypass suffering—it comes through obedience. The cross is not a detour from glory; it is the way glory is revealed.

And yet, as Jesus carries out the mission the Father gave Him, something deeper is happening. Jesus’ life—marked by obedience, humility, and sacrifice—displays God’s character and reveals who God truly is. In other words, God’s glory is made visible in the faithful mission of the Son.

What’s striking in this passage is that this glory is shared. The Son glorifies the Father, and the Father glorifies the Son. This is not competitive glory; it is mutual. Jesus says it even more clearly in John 13:31: “Now is the Son of Man glorified, and God is glorified in him.” God’s glory is revealed in Jesus, not alongside Him or apart from Him.

But this also tells us something crucial: Jesus’ mission is not the beginning of this glory. The cross reveals the glory God has always had. It flows from something eternal—a shared life and glory between the Father and the Son that did not begin in history.

4. God’s Eternal Life Precedes Creation and Grounds Salvation (v. 5)

Jesus’ mission, then, is not the beginning of God’s glory. It reveals something far deeper. In verse 5, Jesus prays, “And now, Father, glorify me in your own presence with the glory that I had with you before the world existed.” With this single sentence, Jesus takes us back before Bethlehem, before Abraham, before creation itself.

Jesus claims that He shared glory with the Father before the world existed. That means His life and mission do not originate in history; they flow from eternity. The obedience of Jesus, His suffering, and even the cross itself are not God improvising a solution to a problem. They are the historical expression of who God has always been.

This tells us something crucial about God. God did not become relational when He created the world. God did not need creation in order to love. Long before anything existed, the Father and the Son shared life, glory, and love. Creation—and later salvation—flow out of God’s fullness, not His deficiency.

This matters because it reshapes how we understand salvation. Salvation is not God reluctantly fixing what went wrong. It is God graciously inviting humanity into the life He already possesses.

5. The Inevitable Conclusion: The Trinity

At this point, John 17 forces us to reckon with what kind of God this must be. From this passage alone, we are required to affirm several things at the same time:

• There is one true God

• Jesus is distinct from the Father, since He prays to Him

• Jesus shared divine glory before creation

• Eternal life requires knowing both the Father and the Son

• God’s life is relational before the world exists

If we try to say all of this without care, we will end up contradicting ourselves. This is why Christians have historically used a specific word to describe the God revealed in Scripture: the Trinity. The Trinity is not an attempt to explain God fully. It is an attempt to speak truthfully about what God has revealed.

6. A Clear Explanation of the Trinity

Here is what Christians mean when they talk about the Trinity. First, there is one God. Christianity is not polytheistic. We do not believe in three gods. Scripture is unwavering on this point. Second, this one God exists eternally as three distinct persons: the Father, the Son, and the Holy Spirit. They are not the same person appearing in different roles. They genuinely relate to one another. The Father sends the Son. The Son obeys the Father. The Spirit is sent by the Father through the Son.

Third, the Father, Son, and Holy Spirit fully share the one divine life. Jesus does not receive glory later as a reward. He shares in God’s glory before creation. The Spirit shares that same divine life and makes it real and active in us.

So when we say “Trinity,” we mean:

• One God

• Three distinct persons

• One shared divine life

• Eternally relational

This language does not remove mystery. It protects it. It keeps us from saying something false about God while honoring everything Scripture reveals.

7. Why the Trinity Matters

At this point, the doctrine of the Trinity is no longer abstract. It explains everything we’ve seen in this passage. If God were not Trinity—if God were solitary—then love would not be eternal. Love would be something God begins to do once creation exists. Relationship would be something God learns. And salvation would be little more than God fixing a problem He did not anticipate.

But John 17 will not allow us to think about God that way. Because God is Father, Son, and Spirit, love is not something God does occasionally—it is who God is eternally. Before creation, before sin, before the cross, God already lived in a perfect, eternal relationship. Glory was shared. Love was given and received. Life overflowed. That means salvation is not God reluctantly stepping in after things went wrong.

Salvation is God opening the life He has always lived. Eternal life is not a reward added on at the end—it is an invitation into the life of God Himself. This is why the Trinity matters. Without it, eternal life becomes vague and transactional. With it, eternal life becomes relational, personal, and breathtakingly real.

8. Final Call: Participation in the Life of God

So now we return to Jesus’ definition. Eternal life is knowing God. Not knowing about God. Not merely believing certain facts about Him. But knowing Him—personally, relationally, truly. And the good news is that this life is not distant. It is not locked in the future. It is not reserved for the spiritually elite. It is offered now. The Father offers eternal life. The Son makes God known and opens the way through His obedient life, death, and resurrection. The Holy Spirit brings us into that life and makes it real in us. Salvation, then, is not something you achieve. It is something you receive. It is not about climbing toward God. It is about God drawing you into His life. The God who has always lived in eternal love now invites you to share in that love. That is eternal life. That is what Jesus offers.

Discussion Questions:

1. When you hear the phrase “eternal life,” what do you usually think it means—and how is Jesus’ definition in John 17:3 different?

   1. Why do you think Jesus defines eternal life as knowing God instead of living forever?

2. Why do you think Jesus says we can only know God through Him?

   1. What does that tell us about who Jesus is and why He matters so much in the Christian faith?

3. John 17 shows the Father and the Son sharing glory instead of competing for it. What does that tell us about what God is like?

   1. How is that different from how power or glory usually works in the world?

4. If God has always lived in relationship as Father, Son, and Spirit, how does that change the way you think about love and relationships?

   1. What does it say about why God created people in the first place?

5. If eternal life is knowing God and sharing in His life now, what might that change about how you think about following Jesus this week?

   1. What would it look like to grow in knowing God, not just knowing about Him?