In early 2016, a newly published book debuted at #2 on the New York Times bestseller list, behind its author’s other highly successful book at #1. That new book was called Spark Joy.

At its heart, Spark Joy is a book that proposes making decisions on the basis of whether something sparks joy in you. To save you time, here is an AI-generated one sentence summary of the book.

Spark Joy is Marie Kondo’s in‑depth, illustrated, room‑by‑room guide to decluttering and organizing your home using her KonMari method of keeping only possessions that truly ‘spark joy’ when you pick them up.

(The reason I am using AI is because I have not actually read the book. I borrowed it from the library and it didn’t spark any joy in me. Not even a flutter. So I got rid of it.)

For my money, Luke 15 proposes a far better decision-making principle, and it’s also based on the goal of sparking joy. Part of the reason it’s a better principle is because it’s not selfish; it’s not about seeking my own joy but about the priority of seeking joy in heaven.

“Just so, I tell you, there will be more joy in heaven over one sinner who repents than over ninety-nine righteous persons who need no repentance … Just so, I tell you, there is joy before the angels of God over one sinner who repents.” (Luke 15:7, 10)

In verses 20-24 we also read of the joyful celebration of the prodigal son’s father when his son repents and returns home.

What is it that sparks this primary joy in heaven? Repentance—even of just one sinner.

Repentance

At this point, it’s worth a brief little aside to make sure we’re understanding ‘repentance’ and not just adding it to the long list of Christian words we use regularly but, when asked to define them, struggle to articulate an answer. I suspect many Christians would say that repentance is something like: ‘stopping sinful behaviour’.

But the change actually starts with the mind—repentance is a change in the way we think about something. In particular, it’s fundamentally about changing who we think of as the king: I used to think it was me, but now I know it’s Jesus.

That change of thinking then produces all sorts of changes in our actions, including stopping sinful behaviour that displeases and dishonours our king. But these changed behaviours flow from a fundamental change in our worldview. In other words, we repent because we become aware that “the kingdom of God is at hand” (Mark 1:15b)—our life needs to change because there’s a new king who has ascended to the throne. We “repent and believe the gospel” (the gospel being the huge announcement that Jesus is now the king, Mark 1:15c).

Repentance that sparks joy

That definition helps us explain why an individual’s repentance would spark joy in heaven: it’s another person who has recognised Jesus as king and who submits to him; it’s another sinner who is being saved from God’s wrath and gathered (with an uncountable multitude of others, Rev 7:9) around Christ’s heavenly throne to glorify him; it’s another voice to sing his praises in eternity; it’s another soul that will be satisfied by being in God’s presence.

We vicariously experience some of this joy on earth. When you hear about someone becoming a Christian, it makes your day, doesn’t it? It brings you joy. Especially if it’s someone you know. And no doubt the joy in heaven is even more pure and genuine than our earthly joy.

The goal of repentance

These parables of Jesus in Luke 15 are pointing out that repentance is worth striving for. No doubt Jesus is primarily explaining his own mission, but he has also just made the point that we are meant to be his disciples (14:26–27)—and not disciples who lack “saltiness” (14:34–35), not disciples who aren’t prepared to count the cost (14:28).

This goal of generating joy in heaven is a big decision-making principle that should drive our lives and priorities if we are followers of Jesus.

So when we’re assessing our churches, perhaps we should be asking questions like this: are sinners (Christians and non-Christians) being brought to repentance? Is our church evangelistically active and are people becoming Christians (repenting and submitting to Jesus as king)? Are church members growing as Christians—i.e. repenting and making more and more King Jesus-focused decisions about how to live their lives? Is repentance actually happening in our midst? Are our churches creating joy in heaven?

But let’s not keep it at arms length by only talking about our churches. Have I lost my saltiness (if indeed I ever had it)? Am I repenting personally and submitting more and more to Jesus? Or are my Christian convictions barely evident in my life? And am I helping other people to repent by speaking the gospel of Jesus’ kingship to them? Am I sparking joy in heaven?

Let’s keep praying and acting for greater repentance—both in ourselves and in those around us.