Podcast Summary: Timothy Keller Sermons Podcast – "A New Heart"

Host: Tim Keller
Date: August 27, 2025
Scripture: Deuteronomy 30:1–10

Overview

In this episode, Tim Keller explores one of the most profound human questions: Why do we struggle to live as we know we ought to? Using Deuteronomy 30 as a foundation, Keller delves into the concept of the "circumcised heart"—a transformed, spirit-given heart that allows us to love and obey God from the inside out. He addresses the human inability to bridge the gap between knowledge and action and unveils the biblical solution: a new heart, given not by effort but as a gift through Christ.

Key Discussion Points & Insights

1. The Ultimate Human Problem (02:38–08:28)

• Deuteronomy as Moses’ Final Sermons: Keller notes how Moses, knowing he is near death, goes directly to the heart of the matter: humanity’s persistent inability to live out the goodness we already know.

• Diagnosis of the Problem:

  • Humanity knows how to live rightly but can’t follow through, echoing the insight explored by philosopher Jacob Needleman:

    “We know how we ought to live. We just can't do it.” (06:03)

  • Psychology, philosophy, and politics can diagnose the problem and recommend solutions, but cannot impart the power to obey.
  • Quoting a counseling professor regarding the limitations of therapy:

    “If you're looking for a forgiving heart, you're in the wrong department... We can't give you a new heart.” (07:20)

2. The Solution: A Circumcised (or New) Heart (08:29–14:18)

• What is the Heart (Biblically)?

  • More than just the seat of emotion—in Hebrew thought, the heart is the control center of the whole person: feelings, intellect, will, everything.
  • Our hearts are ruled by what we most deeply trust, love, and hope in.

• What is a Circumcised Heart?

  • Not a physical change, but a metaphor for inner transformation.
  • Contrasts mere outward obedience (“serving God because you have to”) with deep inward desire (“serving God because you love to”).
  • Memorable line from Keller’s mentor:

    “The being of God requires a love that cannot just be a response to a requirement.” (12:32)

  • When our deepest delight becomes God himself, duty and pleasure fuse—a theme Keller underscores with a beloved hymn:

    “Our pleasure and our duty, though opposite before, since we have seen his beauty are joined apart no more.” (13:38)

• Biblical Thread: The promise of a new heart recurs throughout the Bible—termed variously as “circumcised heart,” “new heart,” “law written on the heart,” and “being born again.”

3. Three Signs of a New Heart (14:19–23:27)

Keller pulls three diagnostic signs from Deuteronomy 30:6–8: love, obey, and live.

A. Love (15:16)

• The mark: You begin to love God for who He is, not for what He gives or does for you.
• Jonathan Edwards’ distinction:

  “People with a new heart love and obey God for the beauty and attractiveness of who he is in himself…They love him as an end in and of himself.” (17:57)

• Illustration: Keller recounts his journey from studying Mozart to enjoy it for a grade, to growing to love Mozart for its intrinsic beauty (19:34).

B. Obey (21:00)

• The mark: Obedience flows from the new heart as a result, not a means, of transformation.
• Changed Life: True conversion isn’t just emotional stirring or intellectual ascent. It leads to a real, growing transformation visible to those around you.
  • “If you’re not changing in the way you actually live, then you don’t have that new heart. You’re just being stirred; your emotions are being stirred, that’s all.” (21:48)

C. Live (22:34)

• The mark: Spiritual life, like biological life, grows organically—gradually, from the inside out.
• Encouragement:
  • Growth is often slow, uneven—like a child maturing. Don’t mistake the lack of dramatic experiences for lack of genuine transformation.
  • “Real spiritual growth, the sign of a new heart, is you don’t just grow mechanically...organically you become a wiser person as the years go by, deeper, happier and sadder at the same time, more tender-hearted...” (23:14)

4. How Do You Get This New Heart? (25:58–37:01)

• Not Through Effort Alone:

  • You can’t simply ask for a new heart in order to be a better person; it must come as a response to seeing what Christ has done.
  • Keller unpacks the meaning of circumcision as a sign of being “cut off” for disobedience.
  • Jesus takes our “cutting off” upon Himself on the cross—fulfilling the penalty of sin and making a new heart possible.

• The Cross as the Source of a New Heart:

  • Quoting Isaiah 53, Keller emphasizes Christ’s substitution:

    “He was pierced for our transgressions... he was cut off from the land of the living.” (32:53)

  • The cross, Keller explains, is where the full meaning of circumcision—exile, punishment, and restoration—is realized for us in Christ.

  • “On the cross, Jesus Christ was experiencing the cosmic cutting off that circumcision represented... He was getting what we deserve for not doing the good we know we ought to do.” (33:41)

• How the New Heart is Received:

  • If the reality of what Jesus did moves you, that is a sign God is at work already:

    “You wouldn’t be moved except God’s already working… That’s how you get the new birth.” (36:02)

Notable Quotes & Memorable Moments

• On the Heart’s Role (11:11):

  “The heart controls not just the emotions, but also the thoughts and the actions. Why? Because in the Bible, the heart is the seat of your most fundamental commitments.”

• Keller’s Mentor on God’s Love (12:32):

  “The being of God, the greatness of the being of God demands a love that can't be the response to a demand.”

• Jonathan Edwards on True Spiritual Experience (17:57):

  “People with a new heart love and obey God for the beauty and attractiveness of who he is in himself… They love him aesthetically.”

• Keller’s Mozart Analogy (19:34):

  “It used to be that listening to Mozart was useful, but now it’s beautiful. Beautiful means it’s satisfying in and of itself.”

• On Spiritual Growth (23:14):

  “Real spiritual growth, the sign of a new heart, is you don’t just grow mechanically... organically you become wiser.”

• On Christ’s Sacrifice (33:41):

  “On the cross, Jesus Christ was experiencing the cosmic cutting off that circumcision represented... He was getting what we deserve for not doing the good we know we ought to do.”

• On Receiving a New Heart (36:02):

  “You wouldn’t be moved except God’s already working... That’s how you get the new birth.”

Timestamps for Important Segments

• The Ultimate Human Problem – 02:38–08:28
• The Solution: Circumcised Heart – 08:29–14:18
• Signs of a New Heart – 14:19–23:27
• How to Receive a New Heart – 25:58–37:01
• Key Quotes and Illustrations – 11:11 (heart defined); 19:34 (Mozart analogy); 33:41 (cross and circumcision)

Conclusion & Takeaways

Keller’s sermon challenges listeners to reflect deeply: Have you received a new heart, or are you merely obeying out of duty? The circumcised heart—a gift received by grasping the depth of Christ’s sacrifice—is the only cure to humanity’s age-old problem: knowing what is right but lacking the power to do it. Spiritual transformation is gradual and organic, evidenced by a growing love for God, obedience flowing from delight, and an increasing experience of spiritual life.

If you discover your heart is moved by Christ’s work, Keller says, that is evidence God is already at work within you. The response is to trust, rejoice, and seek further growth by beholding the beauty of the gospel.

For more sermons and resources, visit Gospel in Life