“Mercy On Those Who Doubt”

Scripture Text: Genesis 17:15-18:15

April 07, 2024 – 8:15 & 11:00 a.m. Morning Services

Faith Presbyterian Church, Tacoma, WA

                                                        Rev. Nathaniel H. Gutiérrez


This morning we will be returning to Genesis 17, where we will continue a series I have been preaching through called “Gleanings in Genesis.” This is a series that highlights certain passages throughout Genesis – this foundational book of the Bible.

Up to this point in Genesis, God has visited Abraham several times to remind him of his covenant promise to Abraham – that he will bless him with a child through Sarah, making him the father of a great nation. Now nearly 25 years have passed by, and Abram is 99 years old, and Sarah is past her child-bearing years, and they still have no children together.

But now God appears to Abraham repeating his covenant promises to him for a third time, confirming his promises to him once again.

It is here where we pick up in the narrative. I’ll begin reading in Genesis 17, verse 15.

The Reading of God’s Word

Genesis 17:15   And God said to Abraham, “As for Sarai your wife, you shall not call her name Sarai, but Sarah shall be her name. 16 I will bless her, and moreover, I will give you a son by her. I will bless her, and she shall become nations; kings of peoples shall come from her.” 17 Then Abraham fell on his face and laughed and said to himself, “Shall a child be born to a man who is a hundred years old? Shall Sarah, who is ninety years old, bear a child?” 18 And Abraham said to God, “Oh that Ishmael might live before you!” 19 God said, “No, but Sarah your wife shall bear you a son, and you shall call his name Isaac. I will establish my covenant with him as an everlasting covenant for his offspring after him. 20 As for Ishmael, I have heard you; behold, I have blessed him and will make him fruitful and multiply him greatly. He shall father twelve princes, and I will make him into a great nation. 21 But I will establish my covenant with Isaac, whom Sarah shall bear to you at this time next year.”

Genesis 17:22   When he had finished talking with him, God went up from Abraham. 23 Then Abraham took Ishmael his son and all those born in his house or bought with his money, every male among the men of Abraham’s house, and he circumcised the flesh of their foreskins that very day, as God had said to him. 24 Abraham was ninety-nine years old when he was circumcised in the flesh of his foreskin. 25 And Ishmael his son was thirteen years old when he was circumcised in the flesh of his foreskin. 26 That very day Abraham and his son Ishmael were circumcised. 27 And all the men of his house, those born in the house and those bought with money from a foreigner, were circumcised with him.

Genesis 18:1   And the LORD appeared to him by the oaks of Mamre, as he sat at the door of his tent in the heat of the day. 2 He lifted up his eyes and looked, and behold, three men were standing in front of him. When he saw them, he ran from the tent door to meet them and bowed himself to the earth 3 and said, “O Lord, if I have found favor in your sight, do not pass by your servant. 4 Let a little water be brought, and wash your feet, and rest yourselves under the tree, 5 while I bring a morsel of bread, that you may refresh yourselves, and after that you may pass on—since you have come to your servant.” So they said, “Do as you have said.” 6 And Abraham went quickly into the tent to Sarah and said, “Quick! Three seahs of fine flour! Knead it, and make cakes.” 7 And Abraham ran to the herd and took a calf, tender and good, and gave it to a young man, who prepared it quickly. 8 Then he took curds and milk and the calf that he had prepared, and set it before them. And he stood by them under the tree while they ate.

Genesis 18:9   They said to him, “Where is Sarah your wife?” And he said, “She is in the tent.” 10 The LORD said, “I will surely return to you about this time next year, and Sarah your wife shall have a son.” And Sarah was listening at the tent door behind him. 11 Now Abraham and Sarah were old, advanced in years. The way of women had ceased to be with Sarah. 12 So Sarah laughed to herself, saying, “After I am worn out, and my lord is old, shall I have pleasure?” 13 The LORD said to Abraham, “Why did Sarah laugh and say, ‘Shall I indeed bear a child, now that I am old?’ 14 Is anything too hard for the LORD? At the appointed time I will return to you, about this time next year, and Sarah shall have a son.” 15 But Sarah denied it, saying, “I did not laugh,” for she was afraid. He said, “No, but you did laugh.”

This is the word of the Lord. Thanks be to God.

Let’s pray together.

We have before us a passage this morning that gives us a snapshot of life with God. God generously and lovingly promises us and his people the most incredible things. Blessings beyond anything we could ever imagine, salvation by grace through faith, and our typical response is, “how could this be?”  This is our frequent pattern. God is gracious, and we doubt his graciousness.

In this interesting passage we are given a beautiful picture of God’s merciful love for those who doubt.

And we will see it displayed in the way God establishes a personal relationship with a doubting people, how he repeatedly assures us of his promises, and how he shows us his love in the midst of our doubts.

Doubting God

Is it wrong to doubt? Many might not say that it is, but the last thing they would want to do is to admit it of themselves! One minister notes that a faith without some doubts is like a human body without any antibodies in it. He suggests that people who go through life too busy to deal with the hard questions about their faith “will find themselves defenseless against…the probing questions of a smart skeptic.” [Keller, xvi]

As fallen human beings, some have more doubts than others, but we all have doubts. And to doubt God is to call into question the reliability of something he has stated to be true. It means that we lack confidence in his word or consider his promises unlikely.

And the reality is, that we all doubt God in different ways at different points in our lives. We especially tend to doubt when things go poorly for us, and when we are not cared for the way we believe we should be.

So why do we question God and doubt him?

We Trust in Ourselves

One reason is because of how we perceive God and how we perceive ourselves.

We see this in the account of Abraham and Sarah before us. God had made a promise, but he did not fulfill that promise in the timing or in the way that Abraham and Sarah had expected. When their expectation of how God should have acted did not come to pass 25 years earlier, they doubted that God would remain true to his word.

Their expectations and their doubt led them to believe that they could not rely on God’s word. So, they trusted in their own judgment instead.

How do we know this? Because in this passage, when God approaches them with the promise of Isaac’s birth for the third time, both Abraham and Sarah individually respond by laughing. Now laughter actually comes up several times over these next few chapters, and in fact the child God promised was to be named “Isaac,” which means, “he laughs.” So, I wanted to look into this question a little more.

What did their laughter mean here? To put it simply, Abraham and Sarah’s laughter was laughter of disbelief and doubt. For Abraham, we see, looks immediately to the fact that they were elderly. And this was not the first time Abraham doubted God. Back in Genesis 15, Abraham questioned and doubted as well, offering up his servant Eliezer to serve as a substitute son for him. Now it is almost as though Abraham is trying to help out God again because Abraham now offers up his son through his servant Hagar, “Oh that Ishmael might live before you!” [Hamilton, 477; Genesis 17:18]

Sarah’s laughter also points to complete doubt and disbelief. We read that “Sarah laughed to herself, saying, “After I am worn out, and my lord is old, shall I have pleasure?” [v.12] And of course this makes some sense, because biologically speaking, their bodies were no longer capable of having children. How would you react if you noticed the name of a 90-year-old woman on our expectant mothers prayer list? No way! That would be impossible. We understand their doubt.

But the point remains that both Abraham and Sarah placed more trust in their own reason than in their faith in the God who created them and promised them this blessing. They chose reason over faith in God.

Tim Keller writes these helpful words on this subject. He writes, “All doubts, however skeptical and cynical they may seem, are really a set of alternate beliefs…. [For example,] you cannot doubt Belief A except from a position of faith in Belief B.” [Keller, xvii] In other words, we need to realize that one of the reasons we doubt God is because we place greater trust in something or someone else than we do in him.

And so, for us to doubt God’s truthfulness, we have to hold something else to be more trustworthy than him. Abraham and Sarah, for example, had more faith in reason and biology than in God’s promise. So, they leaned on their own understanding, placing their wisdom above God’s.

And we do the same thing in our lives.

We Question God’s Intentions

Have you ever asked the question, “What is God doing in this situation?” If you think about it, that question is rarely asked when things are going well. We don’t tend to ask what God is doing, or even doubt him, when things are going our way. No, we tend to doubt God when we feel like he is working in a way that we disapprove of. It is then that we question God’s wisdom in a given situation.

We do this all the time. We disagree with how God handles our lives, thinking somehow that from our vantage point, we would do things better. If we were God, we would save all humanity, or end all evil, hunger and homelessness. If we were in charge, we would end all suffering. Somehow we believe that in our limited thinking, we would do things differently. Maybe if the all-knowing, limitless God, who created the universe and sustains it, could learn a thing or two from us in our high sense of goodness… And sure, we would never say or even allow ourselves to think that statement, but we hold similar beliefs in our hearts.

When we get frustrated, when we face hardships, or when we get upset that things don’t go our way, we get frustrated and wonder why God is doing this to us?! Why do I deserve this hardship? Not realizing that we are revealing our heart’s desire – that we expect God to provide a life for us that is free from hardships and pain – or at least to keep our hardships to a bare minimum. And when that is not the case, we may start to question God’s judgment and begin to doubt.

We might begin to think, “If we cannot trust God, who can we trust?” The unspoken answer is, “ourselves.” We become judge and jury. We believe we get to determine what is right and wrong, and when it is right and wrong.

We reason, like Abraham and Sarah, that if God promised to be with us and to bless us, but then does not give us what we want when and how we want it, we wonder…is he even there at all? We start to doubt him and wonder if he even cares about us. Can we trust him? Or is he a distant, far-away God, who does not concern himself with our personal lives?

And far from being upset with us, God demonstrates incredible patience and love by showing us the truth of who he is.

God Reveals His Intentions

In my Bible classes, I teach something that is incredibly obvious, but that needs to be said nonetheless: just because we think something is true, doesn’t make it true. And just because we dislike something, doesn’t make it untrue.

Additionally, our expectations of God, or our judgments about him, do not determine who he is. The only way we can truly know who God is, is as he reveals himself to us in his Word.

And that is what God does in these two sections of Scripture. He reveals himself to us. Why did God take the time to draw out this text for us?

I noted before that oftentimes when God does not meet our expectations, we tend to wonder if he cares about us, and if he is a distant, far-away God, who does not concern himself with our personal lives. But if you look at this text, that is not what we see.

We see the opposite. Look at the way that God names his children. We see here a picture of a loving Father who changes Abram’s name to Abraham, and then in verse 15 changes Sarai’s name to Sarah. That is personal! When Alicia and I were about to have our first child, it was recommended to us that we not tell anyone the name we had chosen, because otherwise they might try to sway you, or change your opinion, maybe even with a gasp or a look of disgust. We even had a few fake names we’d throw out (to see people’s reactions) before we told them we weren’t sharing our names, and boy was that fun. But the thing is, a name is a very personal matter. That is the parent’s job, and no one else’s.

And far from being an impersonal God, what does God do here? He shows that he is their Father. He sets them apart; he gives them the sign of the covenant and he names his own. He adopts them as his own. He even names Isaac before he is born.

And in addition to that, God takes the time to teach Abraham and Sarah. Through their doubt and through their lack of faith, he patiently takes the time to dialogue with them, and explain this plan for them. In response to Abraham’s offer for God to accept Ishmael instead, God makes it clear that this isn’t just about making babies and having kids. He wants a holy, chosen inheritance. And he had chosen Sarah, and he had chosen Isaac even before his birth. If you browse through this passage, you will find that God refers to Sarah 16 times and specifically highlights, “your wife” several times as well (i.e. – not Hagar).

While God could have opted to go with Hagar and Ishmael, he doesn’t. God doesn’t choose the healthiest, strongest or most child-bearing woman. He chose Sarah. Sarah mattered to God. He chose her, and she mattered so much to him that he named her and insisted that she and she alone would receive his covenant blessing. Even in the midst of Sarah’s doubt, we see here how personal and merciful God is toward her, providing ample reasons for her to believe.

And if that were not enough, God also responds to Abraham’s doubt by not only naming him as well, but reminding him for the third time that he will not preserve the covenant line through Ishmael, but through his wife Sarah and Isaac. Despite Abraham’s faithlessness and doubt, God remains faithful to his covenant promise.

This is who God is. He does not forget his people. Nor does he shame them for having doubts. Instead he responds personally, with love.

God’s Response to Doubt

When we first arrived at our church plant in Peru, I remember witnessing some painful conversations. Many well-meaning people believed that it was their job to shame others into change, and into their ideal of Christianity. They would shame new believers for their choice of clothing, music preferences, lack of punctuality, parenting choices or schooling. If doubts or questions were raised by these new believers, they were shut down with a quick answer. I remember learning that one of the new young women in our church had been led to believe that to be a good Christian meant that she needed to go hungry for several days in order to afford clothes that would look nice enough for church. The environment there was one of toxic performance Christianity and no one felt safe enough to ask questions or to reveal their true struggles.

And to my surprise, I’ve noticed that similar techniques are often implemented among people here in the U.S. And while the intention is well-meaning, it is actually having adverse effects. See, shame is the technique that the Pharisees would use to bring about change. Shame focuses on humiliating others for not measuring up to you, or demeaning someone for not doing the right thing. Scolding someone for not doing the right thing rather than exhorting with love.

You know that terrible feeling. You have heard someone say, “Shame on you!” And implicit in that idea is that you should have known better than to make that kind of mistake. In fact, “You should be ashamed of yourself!”  

The difference between shame and guilt is that with guilt our sins are held up against God’s righteousness, not someone else’s. Guilt pushes us to true repentance, because guilt is something we have when our lives are inconsistent with who God calls us to be, whereas shame is focused more on living in such a way that others approve of your life.

It is no surprise that researchers argue that shame is incredibly harmful. Rather than producing healthy change, it tends to cause people to be better at hiding their sin. Rather than bringing it into the light, shame causes people to hide their struggles and seek to impress others with a false outward shell, a white-washed wall.

And this shame is so toxic because rather than being broken over the sin that we have, we are more concerned about revealing that we struggle at all. I hope we can all hear that. Shame is so dangerous that we are more ashamed that people know that we struggle, than that we have the struggle in the first place. And when it comes to doubt, there is tremendous shame.

And this passage is a powerful example of how God dealt Abraham and Sarah’s doubts by bringing them into the light with compassion. While Sarah hid behind the door of her tent doubting in God’s promise, God called her into the light addressing why she doubted. He spoke into her doubt, and we read later in Hebrews 11:11, that she believed God’s word. See, God’s question to Abraham and Sarah was meant to pull them “beyond their own helpless situation and their own limited resources to the limitless resources of their God.” [Hamilton, 14]

Throughout Scripture we see that God is a God of grace and mercy for those who doubt. And while many do feel ashamed that they doubt, God is the God of doubters. We need not feel shame.

We think of Jesus’ very own disciples who saw for themselves miracle after miracle. Signs that left people stunned as he healed 40-year-old paralytics, how he turned water into wine and used five loaves to feed 5,000. Jesus calmed storms and walked on water. Jesus had power over demons and brought people back from the dead! And even so, with all those miraculous signs, Jesus’ disciples doubted, and Jesus patiently taught them and discipled them.

Consider Thomas. Jesus took the time to show him his scars and let him touch his hands. He revealed himself to Thomas and all the disciples, so that they could believe.

Look how he kindly and graciously brings them to believe and trust in him. This is God’s character. And in the New Testament, Jude 22 commands the people of God to imitate his character. To “have mercy on those who doubt.”

Brothers and sisters, it is my prayer that you would know that we are a church that is fully aware that there is not one person in this building that does not struggle with sin or doubt of some kind. We are all fallen and limited human beings.

Friends, if you are married, you need marriage counseling. I can say that with confidence even if I don’t know you or have ever met you. Don’t let your marriage die a slow unhappy death because you are too ashamed to admit that you need help. If you are a man in this congregation, you probably either struggle with pride, lust, anger or all of the above. If you haven’t talked to someone about your sin – a pastor, and elder or a close friend who can help you grow in that area, wait no longer. Don’t let shame give you a reason to continue to live in sin. If you are a woman, you have struggles as well, but I know better than to go off listing a few of those here. The point is that each and every one of us needs to have mercy on one another, and on ourselves. For our God is a God of mercy who welcomes you to come into the light.

And it seems counter intuitive, but as we look at Scripture, rather than shaming people or ourselves, Jesus extends grace repeatedly, over and over again.. Yes, he calls us to repent, but with that call he extends mercy and grace. God changes people through love and mercy, not through shame.

God Bombards Us with Assurances

Now, one of the most common issues that married men have is that we think to ourselves, “Man, I’ve got a great wife,” or “Man, that was a great meal,” or “Wow she looks beautiful today,” but…we forget to say it out loud. But when we do say those things, it makes a world of a difference. Who doesn’t want to know they are appreciated?! Well in a much deeper and eternally significant way, we need to hear God’s assurances. And God doesn’t give it to us little by little, but he bombards us with his assurances!

God pours his mercy over us again and again because he knows we need to hear it and we have a hard time accepting it. God knows we have doubts. That is why he bombards us with his assurances so that as we process those doubts and wrestle through them alongside all the things that we don’t doubt.

Think of all the ways he does this.

Consider, for example, the sacraments. Here before us today (in the 11am service) we had the sacrament of baptism. Is there any greater picture for us that we have nothing to do with our entrance into God’s covenant? What does the little baby do in baptism? Nothing! What does the washing of the water over his head point us to? The work of the Holy Spirit in his life!

At the Lord’s Supper, we are shown God’s mercy and forgiveness week after week. Every week we are reminded of God’s love for us in Christ’s body and blood, broken and shed for us. Here at this table, we are reminded that by grace we are saved. Not by works, so that no man can boast, but by the life and death of Jesus Christ. Another assurance of God’s grace for us in the midst of our constant doubts.

For in his assurances, we are reminded of our forgiveness as we repent and confess our sins. And we are also reminded of that in the whole of our worship service…in the hymns that we sing, the pieces we hear, the offerings we bring, the blessing we receive…God’s gracious assurances are given to us again and again.

And in the reading and the preaching of God’s word, we are reminded that God is for us, not against us.

The focus is not on us and our doubts or our accomplishments or our failures. The focus is on Jesus and his accomplishments. His work on our behalf. His grace!

When we consider that we have all these blessings, including our very salvation, we begin to realize that while we may have doubts and questions, we also have mountains of answers and abundant reason to hope because of what we do know and do see. What better place to be in our moments of doubts than in his house, with his people, surrounded by his assurances.


So, in conclusion, may we remember that our God is God who pours mercy on those who doubt. He is a God who knows our struggle and meets our struggles.

As we consider the sheer number of ways that God reassures us of his faithfulness to us, in our weekly Christian Sabbath, in his daily provisions, in our daily interactions and in the health that we still enjoy, may we see that this is a personal reminder that he cares about our doubts and our questions.

He knows we need assurances, and that is why he writes us notes (the Scriptures), he sends us flowers and trees and clouds and shooting stars, he blesses us with sunshine and nature, with friends and family and fellowship so that we remember. He pours blessings down upon us, again and again to show us that he is faithful to us and has not forgotten us: that he is who he says he is, and he will be with us until the end of the ages and for all eternity.

And this is the beautiful part of all this: God doesn’t need to do any of this. But he chooses to, because he loves us, and he knows how small and weak our faith is. That we believe but that we need help with our unbelief!

This is our personal God! A God who meets us with mercy in our doubts and whose mercy endures forever on this earth, and into all eternity. Amen.

Sources Used in this series

Brueggemann, Walter. Genesis: Interpretation: A Bible Commentary for Teaching and Preaching. Atlanta, GA: John Knox

Press, 1973.

Hamilton, Victor P. The Book of Genesis: Chapters 1-17. The New International Commentary on the Old Testament. Grand

Rapids, MI: Eerdmans Publishing Company, 1990.

Hamilton, Victor P. The Book of Genesis: Chapters 18-50. The New International Commentary on the Old Testament. Grand

Rapids, MI: Eerdmans Publishing Company, 1995.

Hollander, Aaron T. “Covenants of All Flesh: Earth Community as Grounds for Biblical and Biological Identity.” Currents in

Theology and Mission 39 (2012): 122–30. https://search-ebscohost-com.wscal.idm.oclc.org/login.aspx?direct=true&db=oah&AN=OTA0000058117&site=ehost-live.

Horton, Michael. People and Place: A Covenant Ecclesiology. Louisville, KY: Westminster John Knox Press, 2008.

Keller, Timothy. The Reason For God: Belief in an Age of Skepticism. New York, New York: Dutton, 2008.

Waltke, Bruce K., and Cathi J. Fredricks. Genesis: A Commentary. Grand Rapids, MI: Zondervan, 2001.

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