Scripture Luke 17:5-10
The apostles said to the Lord, “Increase our faith!” The Lord replied, “If you had faith the size of a mustard seed, you could say to this mulberry tree, ‘Be uprooted and planted in the sea,’ and it would obey you.
“Who among you would say to your slave who has just come in from plowing or tending sheep in the field, ‘Come here at once and take your place at the table’? Would you not rather say to him, ‘Prepare supper for me; put on your apron and serve me while I eat and drink; later you may eat and drink’? Do you thank the slave for doing what was commanded? So you also, when you have done all that you were ordered to do, say, ‘We are worthless slaves; we have done only what we ought to have done!’ ”
Sermon
As members of Union Presbyterian Church,
we live to serve our Lord, our congregation, our community, and our world…
These words are printed on the covers of our bulletins every week, the beginning of our Mission Statement, and they describe the DNA of this congregation, as well as the DNA of Jesus’ teachings. Today, Jesus shares a parable that describes this in uncomfortable language. But before we get to that parable, let’s talk first about faith.
Faith, in one way or another, is what brings us together today. Faith is something that might have been introduced to us before we could speak, when our eyes could only focus on the faces of the people who held us in their arms. Or maybe it is something that found us in young adulthood, or in later years. Maybe our faith is brand new. Maybe our faith blossomed when something awful happened to us, during a time of crisis or challenge. Or, our faith may have been challenged by an awful experience or period in our lives.
We often think of faith as conviction about points of doctrine or dogma: One God in three persons, the Holy Trinity; Jesus as the only-begotten Son of God, belief in whom is essential for salvation. And it’s true, these things are usually a part of the Christian faith. But faith is more complicated than that. It’s more nuanced. Reformer John Calvin, in his “Institutes of the Christian Religion,” defined faith as,
“…a firm and certain knowledge of God's benevolence toward us, founded upon the truth of the freely given promise in Christ, both revealed to our minds and sealed upon our hearts through the Holy Spirit.” [i]
Calvin includes doctrine in his definition. But notice what comes first: a conviction that God loves us, a sense that God’s essential attitude towards us is one of caring and gentleness and goodness. And that conviction is not merely intellectual. It is sealed, it is stamped upon our hearts in such a way that we long for it to be true.
The first day of my sophomore year of High School, I walked into in a class full of honors English students, every one of whom was much cooler than I was. And at that age and in that places, one aspect of “coolness” was a heavy dose of cynicism about religion. One boy in the class recognized me from years ago, when we were both in the second grade together; after that year he’d transferred to the public school. He greeted me by saying, “I remember you. Weren’t you the kid who wore a rosary on her belt?” I admitted that, yes, that was me. There followed a conversation that I don’t remember in detail, except that it included all kinds of poking fun at me for being religious. Me being me, I finally said, “Don’t you want to have faith?” I could see immediately that the response to that was more amusement. But that made all the sense in the world to me. (Post Script: That boy is now a man of faith, and a friend.)
Faith is trust in God. We can question and debate points of doctrine, we can wonder how this or that might be true. But what underlies it all is a heart-thing, not solely a mind-thing. And one aspect of that heart-thing is a desire for more.
Doubt is not the opposite of faith. Doubt is an essential part of faith. It’s usually a sign of a questioning heart. It’s always an opportunity for our faith to mature. The opposite of faith isn’t doubt; it’s apathy.
Our passage begins with the disciples begging Jesus, “Increase our faith!” This is because Jesus has just been sharing some hard wisdom about our responsibilities as faithful people, specifically, our responsibility both to avoid causing others to sin, and our responsibility to forgive one another. Not just once, but repeatedly. Here, Jesus says, as many as seven times forgiveness for the same person in a single day. Apparently, this hit Jesus’ inner circle hard. No wonder they ask for an extra helping of faith to help them do this difficult thing.
Jesus’s response is very interesting. He talks about faith the size of a mustard seed—which is to say, just the teeniest little bit of faith—being capable of doing improbably enormous things, like, uprooting a mulberry tree and planting it in the sea. Jesus seems to be hinting that, we don’t need an increase in the amount of our faith; we need to trust it for what it is. He’s encouraging faith of quality, not quantity.
Faith that seems wobbly can show up for us when we need it most, if it’s something we love. We need to love our faith… that might sound odd. But our trust in God is a gift. Faith is a precious gift. In some circumstances it can be fragile, something that can be damaged. But it is also something that can be repaired and strengthened. Again, quality, not quantity.
One author writes,
In the 21st century, we may have less interest in replanting trees in the ocean than in even more improbable feats like ending international conflicts, or poverty and hunger, or racism and xenophobia, or—perhaps most urgent of all—reversing global warming. Would faith of mustard-seed scale move us to bold action, even when the prospects of success seem so slight? [ii]
Filled with trust in God, we can hear this parable for what it is. For one thing, it’s describing life in first century Judea, a culture in which slavery is active and accepted as a fact of life. This was not the same as the brutal, race-based chattel slavery that afflicted our country, whose legacy is still with us. But it was still a human relationship in which some were owners, and some were owned.
Jesus describes, very matter-of-factly, a situation in which the owner is served, and the slaves serve, holding our allegiance to God side-by-side with that fact of life for that time and that place. As slaves to God, we don’t get a cookie for doing exactly what’s expected of us. This is the relationship. God owns us, so we serve.
And yet… this is also a hyperbolic, somewhat warped understanding of our relationship with God. Jesus’ words are designed to shock us. Faith that is based on fear and trembling before a power we believe is out to smite us at the first slip is hardly the faith Jesus encourages elsewhere in the gospel of Luke. In chapter 12 there’s another parable about a master and servants in which the master serves the servants because he is so pleased with their faithfulness (Luke 12:35-38).
Faith that is founded on love, on the other hand, is transformative. Loving God and knowing that we are loved by God results in a relationship of trust. In that relationship, serving God and serving one another becomes a joyful act of gratitude, one that deepens faith and restores our souls.
As members of Union Presbyterian Church,
we live to serve our Lord, our congregation, our community, and our world.
In just a few moments, our elders will serve the bread of heaven and the cup of salvation to all who seek a deeper connection with God: a communion with Christ and with one another. And as they serve you in the pews, you will, in turn, serve one another, because that is what our faith leads us to do. To welcome all to the table, to ensure that all are served.
Who is served? God is served; our neighbor is served. Who serves? God serves us, and we serve one another. And by that service, the mustard seed that is our faith spreads and grows and takes on new life, within us and among us, as well as out in the world, where it is so deeply needed. With God’s love and encouragement, we live to serve our God, our congregation, our community, and our world.
Thanks be to God. Amen.
Endnotes
[i] John Calvin, Institutes of the Christian Religion, 3.2.7, 1:551.
[ii] John T. Carroll, “Commentary on Luke 17:5-10: “Would faith of mustard-seed scale move us to bold action, even when the prospects of success seem so slight?” Working Preacher, October 5, 2025. https://www.workingpreacher.org/commentaries/revised-common-lectionary/ordinary-27-3/commentary-on-luke-175-10-6.