The stories of Rahab and Achan serve a greater purpose in the book of Joshua when they are understood as literary foils that complement one another and not just as isolated units. These two characters and their fate shed light on each other and make the same essential point from two opposite ends. They both demonstrate that nobody can presume upon the basis of their bloodline whether the covenant promise of God is for them or not. In other words, it is not the children of the flesh who are the children of God, but the children of promise are counted as Abraham’s offspring (Rom. 9:6-8; Gal. 3:7-9).
Rahab: A Daughter of Promise
Who is the true child of Abraham? For whom does the promised land rightly belong to as an inheritance? Answer: the one who is a child of Abraham by faith. Rahab demonstrates this family trait by her confession to the two Israelite spies. By it she proves herself to be a true spiritual descendant of Abraham. In her words,
The Lord your God, he is God in the heavens above and on the earth beneath (Josh. 2:11).
Astonishingly, this is the very confession that Israel was instructed to make on the basis of the powerful work of redemption God had begun—by redeeming them from Egypt—and promised to complete—by bringing them into the promised land!
And because [the LORD] loved your fathers and chose their offspring after them and brought you out of Egypt with his own presence, by his great power, driving out before you nations greater and mightier than you, to bring you in, to give you their land for an inheritance, as it is this day, know therefore today, and lay it to your heart, that the Lord is God in heaven above and on the earth beneath; there is no other (Deut. 4:37-39).
Paul tells us that faith comes by hearing, and hearing through the word of Christ (Rom. 10:17)—so what explains Rahab’s confession of faith? Notice the first words Rahab speaks to the spies,
I know that the Lord has given you the land, and that the fear of you has fallen upon us, and that all the inhabitants of the land melt away before you. We have heard how the Lord dried up the water of the Red Sea before you when you came out of Egypt, and what you did to the two kings of the Amorites who were beyond the Jordan, to Sihon and Og, whom you devoted to destruction (Josh. 2:9-10).
To the amazement of the spies, Rahab reveals to them that the Lord their God had outpaced them—as he always does! He had already gone into the land ahead of his people by means of his word, a word of redemptive events that he had accomplished 40 years earlier. This means that for years the Canaanites knew that the God of all the earth was thundering toward them to soon strike the land in judgment. But the kings and cities of the land hardened their hearts against this word (save Gibeon) and so sought to resist and war against the Lord to their destruction.
But snug in the wall of Jericho was the heart of a single prostitute humbled by the Spirit of Christ to receive this word by faith and seek mercy in the God of Israel. The word she had heard was one of impending judgment upon the inhabitants of the land, including herself, but it also revealed a God who is powerful to save and abounding in mercy toward his people. By faith she knew that the only way to gain her life was to lose it, that is, to denounce her city of Jericho and her entire land for that matter, and abandon herself completely to the mercy of God. This mercy will fully embrace her (and her family) in the midst of a crumbling city from which she escapes unscathed (6:25).
Rahab’s confession and her actions demonstrate that even though she was a Canaanite prostitute on the surface, her ultimate identity was that of a daughter of Abraham, a child of Israel by faith. Though Abraham’s blood did not run through her veins, his faith did, and so she proved herself a descendant and therefore an heir to the land and the promises of God.
Achan: A Son of Curse
Achan, on the other hand, though connected by his family line to Abraham, was not a true child of Abraham because he did not act in faith. He was not a true child of the promise because he broke faith and so proved himself to be nothing more than a Canaanite deserving God’s wrath. While Rahab had denounced the land, Achan identified himself with the pagan city targeted for divine destruction by desiring its treasures and taking what was not his, just as his mother Eve had once done.
When I saw [ראה] among the spoil a beautiful cloak from Shinar, and 200 shekels of silver, and a bar of gold weighing 50 shekels, then I coveted [חמד] them and took [לקח] them (Josh. 7:21).
So when the woman saw [ראה] that the tree was good for food, and that it was a delight to the eyes, and that the tree was to be desired [חמד] to make one wise, she took [לקח] of its fruit and ate (Gen. 3:6).
Because of this even though he himself had passed through the Jordan on dry ground, was circumcised with the rest of Israel, and heard the wonderful promises of God, he ultimately identified with the kingdom of Satan, revealing that his allegiance was supremely with his father, the devil (Jn. 8:44). For this reason the gavel of God’s judgment came thrashing down upon him in a heap of stones.
The covenant signs were merely external for Achan and he hardened his heart to the word of the Lord; he did not continue in faith and was therefore destroyed along with the rest of his family (compare this with the salvation Rahab’s family experienced). Achan teaches us a hard lesson: ethnicity and bloodlines alone cannot secure the blessing of God, nor shield one against his judgment—these are obtained by faith alone.
Rahab and Achan: Hope and a Warning
Salvation came to a Canaanite because of her faith, while judgment came upon an Israelite because of his disbelief. Both point to the reality that only true descendants of Abraham can dwell in the land with the Lord. And who are the true children of Abraham? Those, like Rahab and unlike Achan, who share in his faith. Paul will make this point explicit:
Know then that it is those of faith who are the sons of Abraham. And the Scripture, foreseeing that God would justify the Gentiles by faith, preached the gospel beforehand to Abraham, saying, “In you shall all the nations be blessed.” So then, those who are of faith are blessed along with Abraham, the man of faith (Rom. 3:7-9).
For not all who are descended from Israel belong to Israel, and not all are children of Abraham because they are his offspring, but “Through Isaac shall your offspring be named.” This means that it is not the children of the flesh who are the children of God, but the children of the promise are counted as offspring (Rom. 9:6b-8).
Those who are of faith are blessed along with Abraham (Gal. 3:9).
Achan, on the one hand, strongly warns us from presuming upon the means of grace (HC 65; WSC 88) and never actually receiving God’s promised salvation by faith. Rahab, on the other hand, is a beautiful picture of hope, for God has not given his Son only to a single people group, but to the world, so that “whoever believes in him should not perish but have eternal life” (Jn. 3:16).