Commentary on Genesis 15:1-12, 17-18

Genesis 15 explores the significance of God’s promises to Abraham and Sarah about descendants and land.

Their names are spelled Abram and Sarai until they are changed in Genesis 17, but we will use the traditional names throughout this study. In both stories in this chapter, the patriarch initially expresses doubt about God’s promise.

The gospel has been defined as God’s good news for our bad situations. Our bad situations are often our sin and our guilt, but bad situations often involve economic and health issues, broken or troubled relationships, or feelings of meaninglessness. Preaching the gospel means to articulate the gospel in such an inclusive way that hearers will find good news for their bad situations — whatever they are.

In the case of Sarah and Abraham, their first “bad situation” was their inability to have a child despite the promise in Genesis 12:2 that God would make of them a great nation. Abraham had become so desperate that he proposed to adopt his servant Eliezer of Damascus as his heir.

God challenged this “Plan B” of Abraham and Sarah and said that only their naturally born child would be their heir. The Lord took Abraham outside, pointed him to the sky, and urged him to count the stars. That’s how many children you will have. Abraham thought this was a good idea. We do not know what Sarah thought of this proposal (wink, wink). Clearly this promise had the long view in focus: with the passing of generations the descendants of Abraham and Sarah would number in the thousands or even the millions. How like God: when the promise was hard to believe, God upped the ante.

This little story climaxes in verse 6. Abraham believed the Lord. That’s what humans are supposed to do with God’s promises — trust them, accept them, and rely on them. The key to this verse — and possibly to the sermon — is the word “righteousness.” Righteousness in the Bible means living up to the obligations inherent in a relationship. In Genesis 38 Tamar was willing to do anything — including sleeping with her father-in-law Judah — to fulfill her obligation to bear a child for her deceased first husband Er. Hence she was called righteous by Judah.

But verse 6 is ambiguous, even ambivalent. As the note in the NRSV indicates, the words “the LORD” in the second half of the sentence “translates” the Hebrew word “he.” Hence we should read: “And he believed the LORD; and he reckoned it to him as righteousness.” This could mean: Abraham believed the LORD; and the LORD reckoned it to Abraham as righteousness. In this case Abraham trusted God’s promise, and God indicated that the patriarch had fulfilled the obligations of his relationship with God by such trust.

But this sentence might also mean: Abraham believed the Lord; aye, Abraham reckoned that God’s doubling down on the promise was God living up to the obligations of his relationship to Abraham and Sarah. How typical of God. When we have trouble believing a promise, God makes the promise even better.

In verses 7-12 and 17-18 Abraham again has trouble believing the promise, this time the promise of the land: “How am I to know that I shall in fact possess it?” God told Abraham to take a series of animals, cut them in two, and lay each half opposite its counterpart. Then, at sunset, a deep sleep fell on Abraham, much like the deep sleep that overcame Adam before God took one of his ribs and built it into a woman (Genesis 2:21). The point is not to be missed: Abraham is fast asleep for the rest of the pericope, and he contributes nothing to the making of the covenant after he has prepared the animals.

In a dream or vision Abraham observes a smoking fire pot and a flaming torch passing between the cut up animals. On that day the Lord made with Abraham and Sarah a covenant, saying, “To your descendants I give this land.”

Again, this is God’s good news for their bad situation, but what does this ceremony mean? In making an agreement, our ancient ancestors often invoked on themselves a curse. An eighth-century treaty from a place called Sefire says: “Just as I am tearing the shoulder off this sheep, may my own shoulder be torn from its socket if I violate this agreement.”¹

Abraham and Sarah had a hard time believing the promise of the land. Would it help God says if I would invoke upon myself a curse? That is, may I be cut in pieces like these animals if I don’t fulfill this promise? At other times in the Old Testament God reinforces his promises by “swearing by himself” or “by raising his hand to heaven.” When a promise is hard to believe, God reinforces the promise by putting himself at risk. Now can you believe?

The crucifixion of Jesus is interpreted in a variety of ways in the New Testament and in Christian theology. One way of interpreting it is to say that God took upon himself the curse that was meant for us: Cursed is everyone who hangs on a tree. When God did not spare his own Son, but gave him up for us all, is this not good news that empowers our trust? And is not the God of the Old Testament much like the God of the New Testament in putting himself on the line?

Genesis 15 recognizes that it is sometimes hard to believe when we are in bad situations. But God addresses our bad situations with promises that ring true to our needs, just as God doubled down on the promises to Abraham and Sarah. God lives up to his relationship with us by demonstrating that his news for us is indeed good, that he is willing to risk his very self so that we might believe.