“In fact, though by this time you ought to be teachers, you need someone to teach you the elementary truths of God’s word all over again. You need milk, not solid food!” —Hebrews 5:12

If you were building a house, what would be the most important part?

Most people think of the things they can see: the kitchen backsplash, the light fixtures, the color of the walls. Few would say, “the foundation.” It’s gray. It’s hidden. It doesn’t show up on Instagram.

But every builder knows the truth: if the foundation isn’t right, nothing else matters.

Walls crack. Floors tilt. Doors stick. No matter how beautiful the house looks on the outside, if it rests on a shallow or crooked foundation, it won’t stand for long.

That’s what the author of Hebrews is getting at in 5:12. “By now, you ought to be teachers.” You’ve been believers long enough to be building others up. But instead, you need someone to go over the basics all over again.

Before we can grow up in Christ, we need to make sure the foundation is secure. We need to get grounded in doctrine—not for the sake of head knowledge, but for a faith that lasts.

Doctrine Feels Boring—Until the Storm Comes

Let’s admit it: doctrine doesn’t always sound exciting. Give us a book on prayer or relationships or purpose, and we’re interested. Tell us to study the Trinity, and our eyes glaze over. But what we forget is this: doctrine determines how we see everything else.

Doctrine is to faith what rebar is to concrete. You don’t think about it until something starts to shake. But when life gets hard—when grief hits, when doubt creeps in, when the pressure rises—shallow answers won’t hold you. Only the deep things of God will.

If you want to become a disciple who’s rooted, joyful, and resilient—not just emotionally stirred on Sundays—you need a foundation of truth under your feet.

Let’s look at some of those core truths now. Slowly. Thoughtfully. As if our lives depended on them—because they do.

Who Is God?

Your picture of God shapes everything—how you pray, how you suffer, even how you treat others. Is God distant? Is He moody? Is He loving but powerless? Or is He sovereign and good and near?

Scripture tells us that God is holy. Set apart. Other. He is not a slightly better version of us—He is beyond all we can imagine. And yet, in Jesus, this holy God becomes knowable. He is not just Creator; He is Father. Not just Judge; He is Shepherd.

He is Trinity—three persons, one God: Father, Son, and Holy Spirit. We won’t grasp it fully, but we need to hold onto it faithfully. The God of the Bible is not solitary. He has existed in eternal relationship. Love did not begin with us—it began in God.

When we know what God is like, we stop projecting our wounds or wishes onto Him. We begin to worship, not a god of our imagination, but the God who actually is.

And above all, God is good. Following Him is not only right—it’s wise. It’s not just moral—it’s best. Every command of God is rooted in love, every call to obedience is an invitation to flourishing. The Christian life is not always easy, but it is always good. We never lose by surrendering to Him. As C.S. Lewis put it, “God is not safe, but He is good.”

When we know what God is like, we stop projecting our wounds or wishes onto Him. We begin to worship, not a god of our imagination, but the God who actually is.

Can We Trust the Bible?

For centuries, Christians have believed that the Bible is not just a record of religious experiences—it is the Word of God. Breathed out by the Spirit. Authoritative. True.

The Bible is not just an ancient book—it is a living word. It doesn’t just inform; it transforms. When we read it with open hearts, it reads us. It corrects our distortions. It comforts our pain. It challenges our pride.

But many Christians today treat the Bible like a buffet—picking and choosing what feels right and skipping what feels uncomfortable. That’s not discipleship. That’s customization.

A disciple trusts that when Scripture and our opinions collide, Scripture is right. We don’t worship the Bible—but we do submit to the God who speaks through it.

Who Is Jesus?

If your understanding of Jesus stops at “nice guy” or “moral teacher,” your discipleship will stall before it ever starts. Jesus is not just an example—He is Emmanuel. God with us. Fully divine. Fully human.

He wasn’t created. He wasn’t promoted. He is the eternal Son of God who became flesh. He didn’t just come to offer insight—He came to offer Himself.

He lived the life we could not live and died the death we should have died. His resurrection was not metaphorical—it was physical, historical, powerful. He is not a figure in a book. He is a person you can know. A disciple doesn’t just admire Jesus. A disciple walks with Him, listens to Him, and becomes like Him.

What Happened at the Cross?

Many people today want a crossless Christianity. They want the inspiration of Jesus without the blood. But the cross is the center of our faith.

At the cross, Jesus didn’t just show love—He bore wrath. He didn’t just suffer physically—He stood in our place. The punishment that brought us peace was on Him.

Sin is not just a bad habit. It’s a rebellion that deserves judgment. And Jesus took that judgment willingly. Not out of obligation—but out of love.

Understanding this changes how we see grace. It’s not cheap. It’s not casual. It cost Jesus everything.

What Is the Gospel?

If we’re going to talk about laying a foundation, we have to ask the most foundational question of all: What is the gospel?

The word gospel means “good news,” not good advice. It is not a motivational message or a spiritual to-do list. The gospel is the announcement that something has already been done—for us, not by us.

The gospel is this: Jesus Christ died for our sins, was buried, and rose again—so that all who trust in Him are forgiven, adopted, and made new.

It starts with bad news. We are not okay. We are not basically good people who make occasional mistakes. We are spiritually dead, enslaved to sin, and unable to fix ourselves. The diagnosis is serious—but the cure is glorious.

Jesus lived the life we should have lived—perfect, holy, pleasing to God. Then He died the death we deserved, absorbing the judgment of God in our place. On the cross, Jesus took our sin so we could receive His righteousness. And then He rose from the dead, defeating sin, death, and the devil.

That’s not just the entry point into Christianity—it’s the center. The gospel is not just how we begin the Christian life. It’s how we continue.

Tim Keller often said, “The gospel is not the ABCs of Christianity. It’s the A to Z.” We don’t graduate from the gospel. We never move beyond it—we only move more deeply into it.

That’s why we must learn to preach the gospel to ourselves every day.

Preaching the Gospel to Yourself

You don’t need to hear the gospel just once. You need it every morning—before the lies of shame, pride, performance, fear, and despair have a chance to take hold.

When you sin, you preach the gospel: “There is now no condemnation for those who are in Christ Jesus.” (Romans 8:1)

When you feel insecure: “I am chosen, adopted, and dearly loved in Christ.” (Ephesians 1)

When you're tempted to earn God’s favor: “By grace I have been saved, through faith—not of works.” (Ephesians 2:8)

When you feel alone: “Nothing can separate me from the love of God in Christ Jesus.” (Romans 8:38–39)

The gospel is not a one-time vaccine. It’s daily nourishment.