The Obedience of Faith | Exodus 4:18-31

What Do You Do with a Promise?

Believe it or not, Christmas is right around the corner. (The first Sunday of Advent is 4 weeks from today!) Imagine on Christmas morning, you open a gift and find a parachute. What do you do with a parachute?

If you got creative, you could probably think of a lot of uses for a parachute. But parachutes are made for one thing: to bring skydivers safely down from the sky. You could walk around on solid ground with your parachute on your back, reciting facts about parachutes, and proclaiming your undying love for parachutes, but until you jump, you have not exercised faith in the parachute. Knowledge about parachutes and belief in the existence of parachutes is no substitute for relying on a parachute. What do you do with a parachute? The simple answer is you use it. You pull the ripcord, open the chute, and rely completely on the parachute to keep you safe.

And what do you do with a promise? That’s the question I want to consider this morning. What do you do with the Word of God?

At the burning bush on the mountain of God, God revealed himself to Moses in glory as the Great I AM. From the fire, the LORD spoke to Moses great and precious promises. “I will be with you” (Exodus 3:12); “I promise that I will bring you up out of the affliction of Egypt” (Exodus 3:17); “I  will stretch out my hand and strike Egypt with all the wonders that I will do in it” (Exodus 3:20).

To which Moses responded with questions, objections, and outright refusal. The last words we heard from Moses came in 4:13: “Oh, my Lord, please send someone else.” That is not what you do with a promise from God because that provoked God’s anger (4:14). God refused to accept Moses’s resignation, but what will Moses do?

Exodus 4:18–31 

Moses went back to Jethro his father-in-law and said to him, “Please let me go back to my brothers in Egypt to see whether they are still alive.” And Jethro said to Moses, “Go in peace.” And the Lord said to Moses in Midian, “Go back to Egypt, for all the men who were seeking your life are dead.” 

So Moses took his wife and his sons and had them ride on a donkey, and went back to the land of Egypt. And Moses took the staff of God in his hand.  And the Lord said to Moses, “When you go back to Egypt, see that you do before Pharaoh all the miracles that I have put in your power. But I will harden his heart, so that he will not let the people go.  Then you shall say to Pharaoh, ‘Thus says the Lord, Israel is my firstborn son,  and I say to you, “Let my son go that he may serve me.” If you refuse to let him go, behold, I will kill your firstborn son.’ ” 

At a lodging place on the way the Lord met him and sought to put him to death.  Then Zipporah took a flint and cut off her son’s foreskin and touched Moses’ feet with it and said, “Surely you are a bridegroom of blood to me!”  So he let him alone. It was then that she said, “A bridegroom of blood,” because of the circumcision. 

The Lord said to Aaron, “Go into the wilderness to meet Moses.” So he went and met him at the mountain of God and kissed him.  And Moses told Aaron all the words of the Lord with which he had sent him to speak, and all the signs that he had commanded him to do. 

Then Moses and Aaron went and gathered together all the elders of the people of Israel.  Aaron spoke all the words that the Lord had spoken to Moses and did the signs in the sight of the people. And the people believed; and when they heard that the Lord had visited the people of Israel and that he had seen their affliction, they bowed their heads and worshiped.

Trust and Obey

Exodus 4:18–31 describes Moses’s return to Egypt in trusting obedience to God. At the burning bush, Moses was full of excuses and doubts. But God graciously, patiently overcame Moses’s unbelief, and now Moses obeys. That’s the theme of this passage: Moses trusts and obeys God. The phrase “back to Egypt” appears four times at the beginning, and the passage ends with Moses in Egypt with the elders of Israel, just as God commanded.

While the journey itself spans hundreds miles between Midian and Egypt, the account of the journey moves rapidly through seven brief scenes packed into just fourteen verses. The pace of the narrative is striking, as is the lack of detail. At first glance, the passage almost seems disjointed, and the lack of detail creates some ambiguity. 

The best way to understand this is to think of it as a montage. In movie making, a montage is a sequence of short clips edited together to pack an extended period of time and/or great distance into a brief space. Think of the iconic training montage in Rocky, where Rocky Balboa is shown jogging in his sweats, punching the punching bag, doing one handed push-ups, boxing slabs of meat, and finally climbing the Rocky Steps. 

This is the ancient literature version of a montage, and it’s best not to get sidetracked in speculation about the details that seem to be missing, but to pay attention to how these scenes move the story forward. The point of this montage is not simply that Moses went back to Egypt, but that he went back in trusting obedience to God. 

What do you do with the Word of God? What do you do with a promise? You trust and obey. Faith is taking God at his Word and acting on it, no matter how you feel, leaving the results to God.

When we say faith is not a work, we mean faith is not a billable deed you perform for God’s benefit in order to earn or merit payment from God. We do not mean that faith is inactive or inert. This is evident in every scene of Moses’s journey back to Egypt. In every scene, God speaks and acts, and Moses trusts and obeys.

Leaving Midian

The first matter of business for Moses was to respectfully seek permission from his father-in-law, Jethro. Having a command from God did not absolve Moses of his obligation to show respect to his father-in-law. And there’s no need to speculate about what Moses would have done if Jethro had said no, because Jethro gave his blessing: “Go in peace.” This brief scene reminds us that living by faith may not always feel warm and fuzzy.

We learn in verse 20 that Moses did not return to Egypt alone, but he took his wife and sons. That would be Jethro’s daughter and grandsons. This goodbye was undoubtedly difficult. When you’re tempted to imagine that walking by faith should always be sunshine and roses, remember scenes like this one. Faith is taking God at his word and acting on it, no matter how you feel.

In verse 19, God speaks again, giving Moses the green light to depart: “And the LORD said to Moses in Midian, ‘Go back to Egypt, for all the men who were seeking your life are dead.’” And the very next verse tells us that Moses obeyed: “So Moses took his wife and his sons and had them ride on a donkey, and went back to the land of Egypt. And Moses took the staff of God in his hand” (Exodus 4:20). 

Faith is taking God at his Word and acting on it.

This pattern is common throughout the book of Exodus and other parts of Scripture. First the text tells us what God said to do. Then it tells us that Moses did what God said to do. At first it sounds unnecessarily repetitive, especially when we get to the building of the tabernacle. Chapters 25–31 give detailed instructions for building the Tabernacle. Chapters 35–39 describe (in detail) the construction of the Tabernacle. It sounds repetitive, but the point is that God is to be trusted and obeyed. If God says, “Go to Egypt,” trusting God means going to Egypt.

Even that last detail that “Moses took the staff of God in his hand” is meaningful.  These were God’s last words at the burning bush: “And take in your hand this staff, with which you shall do the signs” (Exodus 4:17).

So Moses begins to obey. But taking God at his Word means leaving the results to God. “And the LORD said to Moses, ‘When you go back to Egypt, see that you do before Pharaoh all the miracles that I have put in your power. But I will harden his heart, so that he will not let the people go’” (Exodus 4:21). It was kind of God to prepare Moses for the struggle that was to come.

Have you ever started to take steps of faith—to put some sin in your life to death or mature in some area—and then quit because living God’s way was slower and harder than you wanted? The bitter feelings or the anxious thoughts or the temptation to sin didn’t go away. Living by faith requires perseverance.

And at this point, God gives Moses a specific message to deliver to Pharaoh: “Then you shall say to Pharaoh, ‘Thus says the LORD, Israel is my firstborn son, and I say to you, “Let my son go that he may serve me.” If you refuse to let him go, behold, I will kill your firstborn son’” (Exodus 4:22–23). 

The phrase “Thus says the Lord” appears over 400 times in Scripture. This is the very first one. Walking in the obedience of faith, Moses spoke and acted as God’s representative, authoritatively delivering God’s very word. And what a word it was—a word of grace and judgment, of life and death, of affection and wrath. 

This is also the very first time in Scripture that Israel is called God’s son—tenderly expressing the father-heart of God toward his people. Hundreds of years later, speaking through the prophet Hosea, God says more about this: “When Israel was a child, I loved him, and out of Egypt I called my son. … It was I who taught Ephraim to walk; I took them up by their arms …. I led them with cords of kindness, with the bands of love” (Hosea 11:1–4). What a way for God to describe himself! He is a father teaching his toddler to walk, bending down to hold his hands.

And now God has a word for Pharaoh. And what do you do with God’s Word? Trust and obey! So God warns Pharaoh, “If you refuse …, behold, I will kill your firstborn son” (v. 23).

But before Moses could deliver that message, there was another matter of obedience in Moses’s life that had to be addressed.

On the Way

We read in v. 24, “At a lodging place on the way the Lord met him and sought to put him to death.”

This scene is so abrupt and ambiguous, the questions pile up like cars on an icy road. To begin with, what? Why would God try to kill Moses after insisting Moses was the man for the job? Also, why was Zipporah’s immediate reaction to grab a knife and perform a circumcision? Also, what is “a bridegroom of blood”?

All the other scenes are straightforward enough, but this scene blindsides us with wrath and death and blood and circumcision. There is no way to sanitize it. It is tense and uncomfortable. Exodus 4:25—“Surely you are a bridegroom of blood to me”—is one of those Bible verses you’ll never find on a coffee mug or on home decor at Hobby Lobby. One scholar starts his study of this passage with these words: “Biblical scholars love this passage because it is totally incomprehensible.”

I grant that some things here are ambiguous, but it is not totally incomprehensible. Enough is clear for us to be edified. It is clear that Moses’ firstborn son was not circumcised. And this detail connects to the preceding verse, where God announced that he would kill the firstborn of Pharaoh as judgment for Pharaoh’s disobedience.

Moses’s failure to circumcise his own son meant that Moses had broken God’s covenant with Abarham. Keep in mind that God appeared to Moses to deliver his people in fulfillment of his covenant promises: “And God heard their groaning, and God remembered his covenant with Abraham, with Isaac, and with Jacob” (Exodus 2:24). A covenant is a solemn bond between God and his people that comes with blessings for obedience and curses for disobedience.

In Genesis 17, God reaffirmed his covenant promises to Abaraham. He promised to be Abaraham’s God and the God of Abarham’s his offspring. He promised to bless and multiply them. He promised to settle them in the Promised Land (cf. Gen. 17:7–8). 

Then God said this to Abraham: “As for you, you shall keep my covenant, you and your offspring after you throughout their generations. This is my covenant, which you shall keep, between me and you and your offspring after you: Every male among you shall be circumcised. You shall be circumcised in the flesh of your foreskins, and it shall be a sign of the covenant between me and you. … So shall my covenant be in your flesh an everlasting covenant. Any uncircumcised male who is not circumcised in the flesh of his foreskin shall be cut off from his people; he has broken my covenant” (Genesis 17:9–11, 13–14).

Moses neglected to circumcise his son (or sons). Moses broke God’s covenant! How could Moses enter Egypt and confront the household of Pharaoh if his own household was outside of God’s covenant? God is a holy God who requires complete trust and obedience.

Though the words are shocking—“the Lord met him and sought to put him to death”—what happens next shows this was God’s fatherly discipline teaching Moses obedience. “Then Zipporah took a flint and cut off her son’s foreskin and touched Moses’ feet with it and said, ‘Surely you are a bridegroom of blood to me!’ So he let him alone” (Exodus 4:25–26). The details are scarce, but it is clear from Zipporah’s swift and decisive action that she knew this was divine judgment for their failure to keep God’s covenant. Circumcision was the father’s responsibility, but Zipporah performed the rite, presumably because Moses was incapacitated.

To our sensibilities, the shocking part of Moses’s encounter with God is the fact that the Lord sought to put him to death. However, the real shock should be the outcome: “So he let him alone” (Exodus 4:26). This does not mean that God tried but failed to kill Moses. If God had meant to kill Moses, he would have killed Moses. Rather, God intentionally “left room” (as one commentator says) for rescue and redemption. Disobedience deserves death, but God graciously left room for Zipporah to act. There is nothing shocking about God’s judgment. It is what we deserve. But this is the mercy of God, and it is shocking because no one deserves it.

No one really knows the exact meaning of the phrase “bridegroom of blood,” other than the brief explanation Moses gives in v. 26: “It was then that she said, ‘Bridegroom of blood,’ because of the circumcision.” Whatever else Zipporah meant, “bridegroom of blood” referred to the blood of circumcision, which atoned for her husband’s life. The LORD sought to put him to death. Zipporah acted in faith, performed the required circumcision, and smeared the blood on Moses’s feet. And the LORD spared his life. As Hebrews 9:22 says, “Indeed, under the law almost everything is purified with blood, and without the shedding of blood there is no forgiveness of sins.”

Moses and Zipporah’s trust and obedience to God was a critical example of faith to the nation of Israel. The circumcision of Moses’s firstborn prefigures the Passover. Just as God “passed over” Moses when Zipporah applied blood to his feet—the doorposts of his body—so God mercifully provided Israel with the blood of a lamb to cover their sin and protect them from the Destroyer of the Firstborn (Heb. 12:28).

And the Old Covenant sign of circumcision foreshadows the New Covenant work of Christ. Through Jesus, God has established a new covenant with a new sign.  Instead of circumcision, baptism is now the sign and seal of God’s promises and the mark of those who belong to God.

Paul explains in Colossians 2:11–14, “In him also you were circumcised with a circumcision made without hands, by putting off the body of the flesh, by the circumcision of Christ, having been buried with him in baptism, in which you were also raised with him through faith in the powerful working of God, who raised him from the dead. And you, who were dead in your trespasses and the uncircumcision of your flesh, God made alive together with him, having forgiven us all our trespasses, by canceling the record of debt that stood against us with its legal demands. This he set aside, nailing it to the cross.”

Sin against a holy God is still a matter of life and death, but God has provided his own Son as the once-for-all sacrifice for your sin. 

Are you trusting in and relying on Jesus to save you from God’s just wrath?

Arriving in Egypt

In v. 27, a new character enters the narrative. “The LORD said to Aaron, ‘Go into the wilderness to meet Moses.’ So he went and met him at the mountain of God and kissed him” (Exodus 4:27). Notice how our first introduction to Aaron occurs with the same focus: God said go, so Aaron went.

And the two brothers were reunited “at the mountain of God,” where, once again, Moses did what God told him to do. Do you remember the end of the burning bush encounter? When Moses asked God to send someone else, God kindly promised to send Moses’ brother Aaron to do the speaking. 

But here’s what God told Moses: “You shall speak to him and put the words in his mouth …. He shall speak for you to the people, and he shall be your mouth, and you shall be as God to him. And take in your hand this staff, with which you shall do the signs” (Exodus 4:15–17).

So when Moses and Aaron are reunited in v. 28, it should be no surprise by now that that’s exactly what Moses did: “And Moses told Aaron all the words of the LORD with which he had sent him to speak, and all the signs that he had commanded him to do. Then Moses and Aaron went and gathered together all the elders of the people of Israel. Aaron spoke all the words that the LORD had spoken to Moses and did the signs in the sight of the people” (Exodus 4:28–30). He spoke all the words and did all the signs—word and deed, show and tell.

Faith is taking God at his word and acting on it, no matter how you feel, leaving the results to God.

And look at the results that God brought about (v. 31): “And the people believed; and when they heard that the LORD had visited the people of Israel and that he had seen their affliction, they bowed their heads and worshiped” (Exodus 4:31). They worshiped by faith. They were still slaves in Egypt. Nothing about their situation had changed. But they received God’s word and acted on it, leaving the results to God.

Conclusion

So what do you do with a promise from God? You grab hold of it and trust it and act on it, no matter how you feel, leaving the results to God.

And perhaps you’re thinking, “If God would just appear to me in a burning-bush-like way and give me specific instructions for my life, I would gladly do what he says.” While God has not given turn-by-turn navigation for your life, God has given you his Word—his written Word. God has revealed that he wants you to seek first the kingdom of God and his righteousness (Matthew 6:33). In 1 Thessalonians 4:3, Paul says, “For this is the will of God, your sanctification.” Later in that letter, Paul writes, “Rejoice always, pray without ceasing, give thanks in all circumstances; for this is the will of God in Christ Jesus for you” (1 Thessalonians 5:16–18).

So for us today, acting on God’s Word looks like confessing our sin and killing it, growing and maturing to be more like Christ, and living for the glory of God in your speech and conduct, because faith is taking God at his Word and acting on it, no matter how you feel, leaving the results to God.