Commentary on Genesis 15:1-6

Under ideal conditions—no clouds, moon, or light pollution, and a full sky view—the naked human eye can see light from just around 3000 stars. Yet using our own galaxy, the Milky Way, as the model, astrophysicists calculate that a typical galaxy contains at least 100 billion stars. Estimates are that there are around 10 trillion galaxies! This means that in the vastness of space, the universe contains upwards of one-septillion stars—or a “1” with 24 zeros after it! That’s more than 133,000 stars for every grain of sand on earth!¹ No wonder God tells Abram to count the stars … “if you can.”

Promise in peril

In Genesis 12:1–3, God promises Abram land, blessing, and descendants. By the time we reach Genesis 15:1–6, Abram has become wealthy and shown a unique trust in God. But with the passage of time, he and Sarai’s confidence in the promise of becoming a “great nation” (Genesis 12:2) begins to wane. At its original utterance, Abram was 75 years old (12:4), and Sarai was 65 (Genesis 12:4; 17:17), well beyond their child-producing years. Paul even describes Abram’s aged body as “already as good as dead” (Romans 4:19). Further complicating matters, Sarai is barren (Genesis 11:30).

Later in Genesis, Abram and Sarai will laugh at the absurdity of this promise in the face of their aging bodies (Genesis 17:17; 18:12). God’s original promise seemed hard enough to believe; it is almost certainly physically impossible now! The promise does not match their reality. So Abram takes his questions directly to God. At issue is less Abram and Sarai’s progeny and more God’s fidelity. Will God keep the promise, even in impossible circumstances? Can God?

Abra(ha)m as a model of faith

The New Testament upholds Abra(ha)m as a model of faith (Romans 4; Galatians 3; James 2:21–23; Hebrews 11:8–22). We might rightly consider, then, what this faith looks like.

In Genesis 15, God reminds Abram, “Your reward shall be very great,” seemingly calling to Abram’s mind the “great nation” God had promised. Abram pointedly asks, “O Lord GOD, what will you give me, for I continue childless, and the heir of my house is Eliezer of Damascus? … You have given me no offspring, so a slave born in my house is to be my heir” (15:2–3). Abram has already trusted God enough to leave the comforts of his family and homeland; how is God now keeping the divine part of the deal?

Some might want to chastise Abram here for being short on trust and heavy on criticism of God. Rather, I suggest this marks Abram as an example of faithfulness. He is honest about things that do not make sense to him. Instead of silently stewing or letting concerns gnaw at his faith, he brings his complaint before God. He dares to hold God accountable. You don’t bring a problem to God if you don’t believe—trust—that God can do something about it.

This is the stuff of faithful lament: reminding God of past promises and deeds, and using that to persuade God to intervene in the current dilemma. And there is a rich, underappreciated biblical tradition of lament that is vital for the honest life of faith (see Psalms 13 and 89; Lamentations; Job; Jeremiah 11:18–23; 12:1–6; 15:10–21; 17:14–18; 18:18–23; 20:7–18).² We might hear Abram’s cry in the opening words of Psalm 13, a classic lament psalm: “How long, O LORD? Will you forget me forever?”

If you are able …

And notice God’s response. In a tender scene, God directs Abram’s gaze upward to the night sky: “Look toward heaven and count the stars, if you are able to count them. … So shall your descendants be” (Genesis 15:5).

God does not punish Abram for his perceived lack of trust. God has not abandoned, and does not abandon, the promise. Instead, God has heard Abram’s lament, and God does something counterintuitive: God ups the stakes! If Abram is concerned about having a single heir at his ripe old age and with his barren wife, how about as many descendants as there are stars in the sky? God gives Abraham a stunning and ever-present visual aid to remind him, every night, of the promise and of God’s fidelity to it. When we’re stuck and struggling to trust, God shows up and makes the promise even better. Just look at all those stars!

Who credits what to whom now?

There are few Old Testament verses more important to the New Testament than Genesis 15:6 (Romans 4:3; Galatians 3:6; James 2:23; Hebrews 11:8–11). It has become central in Protestant sola fide theology. Unfortunately, this verse also has a reputation of being incredibly pesky; the Hebrew is at best ambiguous, plausibly being understood as either the Lord crediting Abram as righteous, or Abram crediting the starry-night encounter with God as righteousness—that is, Abram now trusts God to deliver on the promise, despite all signs pointing to its apparent impossibility.

Just count the stars

Regardless of how one understands this verse, the takeaway is clear: Abram’s trust that God will make of him and Sarai a great nation is renewed. The promise is written in the stars.

While the dominant voice in the Psalms is lament, supporting Abram’s questioning of God, the Psalms also beautifully sing of God’s heavenly handiwork. The stars are called “the work of [God’s] fingers … which [God has] set in place” (Psalm 8:3); they were created by God “to rule over the night” (Psalm 136:9). It is God who “determines the number of the stars; he gives to all of them their names” (Psalm 147:4; see also Isaiah 40:26). And the vast heavens, including the stars, offer praise: “Praise him, sun and moon; praise him, all you shining stars!” (Psalm 148:3).

A ”great nation” would indeed issue from Abram and Sarai. Abram himself will have eight biological sons to his name. His grandson Jacob will be renamed “Israel” (Genesis 32:28) and his wives will birth 12 sons, who become the namesakes for the 12 tribes of Israel. At the start of the book of Exodus, it is said that “the Israelites were fruitful and prolific; they multiplied and grew exceedingly strong, so that the land was filled with them” (Exodus 1:7).

In the New Testament, “children of Abraham” becomes a theological rather than a biological marker, expanding to include Gentiles, anchored around faith rather than bloodline (Matthew 3:9; Luke 3:8; Romans 9:7–8; Galatians 3:7, 29). Preachers should be aware that this reframing can become dangerous, evidenced by texts like John 8:39–59, where Jesus castigates a Jewish group claiming “Abraham is our father” (8:39), saying to them, “You are from your father the devil, and you choose to do your father’s desires” (8:44). Any attempt to exclude Israel/Jews today using these (or other) words must be unequivocally rejected (see especially Romans 9–11).

The preacher may remind the congregation of the old Sunday school song: “Father Abraham had many sons, many sons had father Abraham. I am one of them, and so are you, so let’s all praise the Lord!” The preacher may also invite the congregation into the wonder of this scene, considering that out of this amazing, unfathomable number of stars that decorate the heavens and span galaxies known and unknown, there is a star hung and named for each of us. Perhaps it is a star that Abram and God gazed at, together, when Abram tried to count the stars, and trusted God.

So how does Abram, and how do we, know we can trust God, when what God is promising seems impossible? According to God, you count the stars. And suddenly, what seems impossible appears trustworthy in the hands of the One who made all those stars—too many to count, a number beyond human comprehension. Abram trusts the God who created, named, and hung every star in its place. Because if God can make more stars than there are grains of sand, what can’t God do? This God can be trusted, and will prove trustworthy as Abram’s story continues.

Notes

1. “Star Basics,” NASA, accessed May 30, 2025, https://tinyurl.com/mry92tht; Miles Hatfield and Vanessa Thomas, “Rocket Team to Discern If Our Star Count Should Go Way Up,” NASA, June 3, 2021, https://tinyurl.com/bdeddfzb; Ailsa Harvey and Elizabeth Howell, “How Many Stars Are in the Universe?” Space.com, February 11, 2022, https://tinyurl.com/78wz2ruc.
2. See especially Walter Brueggemann, “The Costly Loss of Lament,” JSOT 36 (1986): 57–71.