Jeremiah 31:31-34 Commentary

When I was in Sunday School, we sang, “Into my heart,/ come into my heart, Lord Jesus./  Come in today,/ come in to stay,/ come into my heart, Lord Jesus.”  As we sang, we imagined Jesus standing and knocking as long it takes for us to faithfully open the door to and invite him into our hearts.

That, however, is a hardly a picture of the God of our text.  After all, Jeremiah 31’s God seems to be sick of knocking on people’s hearts and waiting in vain for them to invite God in.   Hearts are naturally so hardened toward God that no one, on their own, asks the Lord “into” them.

The Jerusalem in which so many of Jeremiah 31’s spiritually hard hearts live is about to fall to Babylonian invaders.  Its conquerors are preparing to haul off many of those concrete hearts to Babylon.  David’s descendants will no longer serve as Israel’s kings.  Jerusalem’s temple will soon lie in ruins.

For most of Jeremiah, the prophet basically tells Israel, “You had all this coming, and this is why.”  Essentially, the prophet insists, Israel deserves her fate because she has broken every covenant God ever made with her.

However, God and Jeremiah are particularly frustrated with Israel’s stubborn refusal to keep her part of the covenant God made with her at Mt. Sinai.  There God graciously showed Israel how to faithfully receive God’s grace by living as God’s obedient children.  God even inscribed that guide to thankful living on two stone tablets.  On them the Lord essentially invited the Israelites to remember to love God above all and their neighbors as themselves.

Israel, however, doggedly refused to live up to her part of the covenant.  She sampled from a whole buffet line of gods.  And even when Israelites did worship the living God, they used images of God to do so.  So Israel ignored the very first two words of her covenant with God.

Yet the Israelites failed not only to be faithful to the God of heaven and earth, but also to each other.  They neglected to love each other as much as they loved themselves.  Israel especially failed to love the most vulnerable citizens among her.

Yet that’s not just Israel’s problem.  You and I confess that it’s also ours’.  Our gods, as Martin Luther once famously pointed out, are whatever or whoever is most important to us.  We naturally serve not the living God, but everything from our own desires to wealth.  You and I also naturally love ourselves far more than we love the people around us, especially people on society’s margins and our enemies.

So when God stands knocking at the door to our hearts, begging us to let God be our God, God’s people still naturally lock God out.  If it were up to us, we’d never let God make himself our God and us God’s children.  On top of all that, we’d never even naturally ask God to unlock our locked and dead-bolted hearts.

However, in Jeremiah 31, the crusty old prophet of doom and gloom, says “But that was then.  This is now.  God’s going to make a new covenant with Israel.”  He announces that God will write this new covenant not on tablets of stone or even pieces of paper, but on people’s hearts.

Of course, that sounds both painful and dangerous.  We might think of it as God tattooing God’s law on us.  However, since tattoos have now gone fairly mainstream, people ahead of trends are being branded.  So we might think of God as branding God’s covenant onto our hearts.  We can almost imagine the ghastly smell God would create by burning God’s law onto our hearts.

Thankfully, then, Jeremiah isn’t talking about God literally branding God’s law onto beating hearts.  He’s, instead, talking about God’s Spirit implanting God’s law in that mysterious center of people from which our desires flow.

Yet there’s still something very painful about God’s writing God’s law on our hearts.  God is, after all, determined to soften God’s adopted sons and daughters’ hearts toward the Lord.  However, for that to happen, sinful practices and loyalties must die.  And since you and I can’t somehow overcome our naturally rebellious natures, God must put that part of us that is selfish and self-centered to death.

In God’s adopted sons and daughters’ sinful selves’ place God promises to put hearts and minds that God softens toward God alone.  God vows to fill hard hearts with a longing to receive God as God.  That is, in fact, one of the benefits of Jesus’ resurrection.  In the Heidelberg Catechism, Reformed Christians profess that God raised Jesus from the dead so that “by his power we too are already now resurrected to a new life.”

In that new life Jeremiah promises that God’s children will “know the Lord.”  There’s a lot to such knowledge.  After all, as one colleague notes, I may know that eating three bowls of ice cream every night is unhealthy.  But that knowledge does me little good unless I act on it.

In a similar way, Jeremiah promises that a day is coming when God’s people will know God’s law.  However, he also promises that they’ll also commit themselves to obeying it by loving God above all and their neighbors as themselves.  God will empower God’s adopted sons and daughters to be both willing and able to obey God’s commands to do justice.  In fact, Jeremiah insists, God’s children will no longer even have to teach each other about God.  Everyone will already know about and serve the Lord.

God bases this new covenant about which Jeremiah speaks on God’s extraordinary grace.  Of course, God related to Israel by grace since the very beginning.  Yet the prophet’s Israel has stubbornly refused to receive that grace with her faithful obedience.  So God promises to fundamentally change her, to fully equip her to receive God’s grace with her faith.  The Israelites will come to recognize themselves as beloved and forgiven.

Jeremiah is speaking of a day when Israel will obey God’s law not because she’s supposed to, but because she wants to.  She’ll long to obey God’s law because God has shaped her hearts and minds that way.  So Israel’s capacity to be faithful and obedient will spring not from some outside constraints, but from the inside.  They’ll do the right thing because they want to do it.

So God’s greatest miracle may not be God’s parting of the Red Sea or rescue of Jonah from the whale.  The greatest miracle may be that God softens stony human hearts, that God equips God’s children to want to do the right thing.

While I attended and after I graduated from college, I worked in a Christian facility that houses teenaged wards of the state.  In the unit where I worked someone had to unlock doors for the resident teenagers to get nearly everywhere.

Those young people were in such a restricted environment because they’d proven to be largely unable to handle freedom.  So workers tried everything to convince them to use their freedom wisely.  We imposed stiff punishments for wrong behavior and give rewards for good behavior.

Yet I never saw any of those adolescents really change because of punishments or rewards.  They sometimes changed their ways to avoid punishment and gain rewards.  But they never really wanted to be good people – unless God had changed their hearts.

Of course, it isn’t just what we used to call juvenile delinquents whose hearts God needs to soften.  After all, even with the Holy Spirit living in God’s people, we too fail to live as faithfully obediently as God has equipped us to live.

That’s why Jeremiah insists those days of complete and faithful obedience aren’t fully here yet.  We see a partial fulfillment of his promise after Judah’s return from Babylonian exile.  The people of Judah do, in fact, at least begin to acknowledge the Lord alone.  They give up worshiping images of God.

In Jesus Christ, of course, Jeremiah’s prophecy finds further fulfillment.  After all, in John 12:32 Jesus says that “When I am lifted up from the earth, I will draw all men to myself.”  In other words, when the authorities crucify Jesus, God writes God’s law on people’s hearts not just in Israel, but also across the world.

However, Jeremiah’s prophecy still awaits its complete fulfillment.  After all, in Romans 11:27 the apostle Paul suggests that God has not yet totally fulfilled the prophet’s promise.  Those who proclaim Jeremiah 31 might want to explore with hearers evidence of that incompleteness.

Yet God has already done a great thing by giving God’s adopted sons and daughters the gift of the Holy Spirit who writes that new covenant on our hearts.  God’s Holy Spirit already equips us to both desire to and keep God’s law.  So those who proclaim Jeremiah 31 might also share concrete examples that branding of God’s law onto people’s hearts.

We can thank God for signs that while God still has work to do, God has already branded hearts with a longing to love God and each other.  However, we also gladly anticipate that day when God will do that great thing fully as we serve the Lord gladly in the new creation.

Illustration Idea

There are countless signs that God hasn’t yet completely fulfilled Jeremiah 31’s prophecy.  They include the racial divisions that continue to plague countless countries, including the United States and Canada.

Yet once in a while we catch a glimpse of God’s new covenant at work.  I think of a white woman who was a member of a historically segregated church in rural southern Virginia.  A car full of drunken, joyriding black teenagers struck and killed her teenaged son.

Yet she told one of my acquaintances, “I don’t understand why I don’t hate those drunken kids.”  The grieving mother then paused before adding, “I guess God has given me a forgiving heart.  All things are possible with God.”

A few years ago a band of white teenagers brutally attacked and killed Jean Sandiford’s black son Michael in Howard Beach, Brooklyn, New York.  His mom, whom people saw reading her Bible during their trial, admits that even the passage of time hasn’t yet erased her pain.

“Sometimes I sit here and cry,” Jean admits.  Yet when talking about the three men who are still in prison for the murder, she says “At night I pray for them.  I ask God to forgive them.”