Timothy Keller Sermons Podcast by Gospel in Life
Episode: Principles of Christian Growth, Part 1
Date: March 2, 2026
Speaker: Tim Keller

Episode Overview

In this sermon, Tim Keller explores the biblical concept of spiritual growth, focusing specifically on what it means to "grow up" in the Christian faith. Drawing from 1 Peter 1:22–2:3 and paralleled by passages in 1 John, Keller unpacks the imagery of spiritual infancy and growth stages within the Christian life. He encourages listeners to recognize the non-linear, often humbling journey of maturing in Christ — and prepares them for deeper practical exploration in future messages.

Key Discussion Points & Insights

1. The Call to Spiritual Growth (00:54–06:37)

• Central Passage: 1 Peter 1:22–2:3. Emphasis on verse 2: “Like newborn babies, crave pure spiritual milk, so that by it you may grow up into your salvation...”
• Main Focus: Instead of discussing practical "how-to’s," Keller centers this sermon on the very fact of spiritual growth: What does it mean to be told to "grow up" as a Christian?
• Three ways of spiritual growth (to be examined in later sermons):
  • Nourishment (craving spiritual milk — the Word)
  • Acceptance (obedience as purification)
  • Exchange (deep sincere love for others)

2. Christianity as a Growth Journey (06:37–14:34)

• Spiritual Stages: Christianity is not simply a status, but a process or journey with stages of development — paralleling physical and psychological growth.
• Parallels in 1 John: Stages of "children," "young men," and "fathers" indicate that believers progress through recognizable phases.
• Quote (Tim Keller, 09:27):
  • “Christianity is not a static thing at all. It’s not just getting into a status... Instead, it’s this great journey, and that’s the glory of it. But it’s also very frightening. Children and youth don’t understand themselves...”

3. The Nature of Spiritual Infancy (14:34–19:44)

• The Comparison: Spiritual babies resemble biological ones — they lack understanding about themselves and need guidance.
• Flesh vs. Spirit:
  • Before conversion, “your whole heart is united in absolute opposition to God as Savior. You want to be your own savior.” (16:43)
  • After conversion, a new power (the Holy Spirit) enters, but the "old system" resists fiercely: “Your pride, your selfishness... is cornered, it’s wounded and now it’s far more aggravated and far more ferocious than it ever was before.” (19:27)
• Quote (Tim Keller, 19:56):
  • “A Christian who’s mature expects the sinful part of their heart to be worse after conversion than it was before. More aggravated, more ferocious, more upset in a corner. Does that surprise you? You’re babes. That’s okay. Everybody starts out that way.”

4. The Necessity of Community & Guidance (19:44–23:36)

• Dependence:
  • Just as children need limits and instruction, so do new Christians — from older believers, the church, and the Word.
• Warning:
  • “Don’t you dare think you can be self-contained little units... Without submitting to wiser heads... you’re going to make a shipwreck of things.” (21:15)
• Challenge to Individualism:
  • It’s not a “cafeteria” of picking and choosing spiritual influences; Christian maturity requires humble openness to help.

5. The Three Stages of Christian Growth (24:29–39:21)

Keller, drawing on John Newton’s letters and 1 John 2:12–14, delineates three broad stages:

Stage 1 – “Children”: Assurance of Forgiveness

• Key Marker: You truly know your sins are forgiven through Christ alone.
• Obstacles: Works-righteousness and emotional instability indicate spiritual infancy.
• Quote (Martyn Lloyd-Jones via Keller, 27:25):
  • “If you are uncertain about the forgiveness of your sins, that in itself is a sin... You are not relying upon the finished and complete work of the Son of God for you on the cross.”

Stage 2 – “Young Men”: Strengthened by God’s Word

• Key Marker: Learning to operate by the Word, not fleeting emotions; perseverance when God feels absent.
• Quote (John Newton via Keller, 31:41):
  • “Stage A, babyhood, was marked by high feelings and little knowledge of the truth. Stage B is marked by lower feelings and growth in the knowledge of the truth.”
• Challenge: To stand on scripture and faith, not on the sense of God’s presence or emotional comfort.

Stage 3 – “Fathers”: Deep Communion with God

• Key Marker: Consistent, disciplined fellowship and experiential knowledge of God (“You have known him who is from the beginning”).
• Description: Routine, daily communion replaces sporadic spiritual highs. Like Moses or Jacob, the mature Christian persistently seeks God’s glory and presence.

6. Marks of Spiritual Babiness & Call to Humility (39:21–46:42)

• Sins of spiritual infancy:
  • Instability, lack of discernment, self-centeredness, desire for spectacle, impatience with spiritual discipline.
• Quote (Tim Keller, 42:12):
  • “It’s going to be hard for some of you because a lot of you are very smart people. And natively you’re smarter than the people who are here who are spiritually much more mature than you... but you’ve got to see it.”
• Encouragement:
  • Recognizing immaturity is not to despair, but to hope for growth; submit humbly and seek instruction and accountability.
• True Goal:
  • “Stop being childish, and become childlike... You want childlikeness? Look at Jesus. He loved his father, was dependent on his father, completely artless and genuine... You want to be childlike but not childish.” (45:18)

Notable Quotes & Memorable Moments

• On spiritual infancy:
  • “When you become a Christian, all kinds of things begin to happen to you. You don’t understand them... you don’t understand yourself. You need help. You need guidance as desperately as a child needs it...” (17:14)
• On resistance to growth:
  • “If you really think that you can move ahead in the Christian life without submitting to wiser heads... you’re going to make a shipwreck of things.” (21:15)
• On the need for assurance:
  • “Do you know that nothing can snatch you out of His hand? ... You’re always feeling so unworthy and always wondering whether God really loves you. Because you look at your failures... You still don’t understand the gospel.” (29:24)
• On adolescence in faith:
  • “You never get out of adolescence until you learn to say: Everything is necessary that He sends and nothing can be necessary that He withholds. You stop the self-pity and the temper tantrums of babies.” (37:06)
• On childlikeness in Christ:
  • “The goal is to stop being childish and become childlike. ... There you have the perfect childlike Jesus. ... You want to be childlike but not childish.” (45:18)

Important Segment Timestamps

• Reading & Intro to Passage – 00:54
• Focus on Growth, Not Yet "How-to" – 05:43
• Comparison to Physical Maturity & Stages – 08:11
• Nature of the Inner Battle Post-Conversion – 15:47
• The Necessity of Community – 19:44
• Stages of Growth Introduced (John Newton) – 24:29
• Stage 1: Assurance (Children) – 26:29
• Stage 2: Word Strength (Young Men) – 31:55
• Stage 3: Communion (Fathers) – 36:47
• Marks of Spiritual Babiness – 41:27
• Final Appeal: Be Childlike, Not Childish – 45:18

Conclusion & Takeaways

• The Christian life is a dynamic, humbling journey of growth, marked by distinct stages paralleling biological maturation.
• True progress requires recognizing your need for guidance, humbly accepting your current stage, and aspiring to maturity — especially by distinguishing between childishness and Christlike childlikeness.
• Assurance of forgiveness, steadfastness in God’s word, and persistent communion with God are foundational milestones of this journey.
• Keller closes by encouraging reflection and resolve: don’t be content to remain a spiritual baby — “Resolve tonight, I’m going to grow up.” (46:01)

For more teaching and resources, visit gospelandlife.com.