Aliens, Angels, and Why God Flooded the World

Have you ever thought about whether the Bible has anything to say about aliens, about whether their might be intelligent life out there somewhere? If you’ve ever heard someone ask or try to answer that question, chances are they may have turned to Genesis 6.

Some people speculate that this mysterious group in Genesis 6:4 called “the Nephilim” may be extraterrestrials. These are the aliens. This is the Bible’s Roswell and Area 51.

But before you get the wrong impression about this sermon, let me play the spoiler and say up front that I don’t find any shred of indication anywhere in the Scriptures that there is intelligent life anywhere in God’s whole wide universe other than Planet Earth. Not even in Genesis 6. Christians who are whole-Bible people, and keep those Bibles open, have no reason whatsoever to suspect that God put intelligent, material life elsewhere in the universe. So, here at the outset of this very tricky passage, let’s at least rule out the aliens-came-to-earth view of the Nephilim.

Of course, the Bible does teach that there are spiritual, intelligent beings made by God, called angels. This passage is not about aliens, but a question it raises for some is, Who are these “sons of God” mentioned in verse 2, who took as wives “the daughters of man”? Were there angelic-human hybrids prior to Noah’s flood? The alien view may be out, but the angel view is one of the two main views through church history as we’ll discuss in a few minutes.

Clarity and Care

But before we get into all that, let me just admit here up front that this is a tough passage. There is something to say here about living with ambiguity in Scripture. Not every passage is crystal clear. We believe in the clarity or “perspicuity” of the Scriptures, which means we believe the main things are clear, but not that all things are clear. And this is one of those passages that is not manifestly clear. Passages like this remind us that we’re not God; we don’t know everything; and we can’t have a black and white, 100% certain answers about everything in the universe.

Also, what you might find this morning is that if we really pay attention to this text before us, and its context, and not jump to speculation about aliens and angels, and feed the wild side of our imaginations, we might find there’s more clarity in these verses than it may seem like at first. It is a great shame that so many Christians, not just today, but throughout church history, have paid so little careful attention to what God actually says in the Bible. Oh how many problems are cleared up when we really wrestle carefully with the actual words God has revealed to us, and ask hard questions, and make patient observations, instead of impatiently running to speculation.

Why God Flooded the World

Before we depart on our quest to discover who these Nephilim are, let me say something especially to the kids in the room. I’m teaching our new kids Sunday School this fall, and we’re working our way through Genesis as well. Originally I was assigned to preach on Cain and Abel two weeks ago, and I was excited to get help on that from our (very good) kids curriculum called The Gospel Project. But then we switched things around in the series, and my Genesis 4 assignment became Genesis 6 and the Nephilim! And guess what — there’s no help in the kids book for that.

So, kids, listen up. This is a very short little story that’s not in the Sunday School book, but it is in the Bible. It’s a very mysterious passage. No one today is totally sure what all of it means, but I think we can make a good case for one understanding, at least in part. And actually this passage, as strange as it is, has some very important things to teach us about God and ourselves and the world — and it’s surprisingly relevant to life today even in this crazy election cycle (which very well may be the new normal in this nation, not the exception we hope it is). After all, “All Scripture is breathed out by God and profitable” (2 Timothy 3:16). That includes Genesis 6:1–4.

But before we go there, let’s get our bearings by seeing how this fits into the larger passage, and begin with two points from verses 5–8. This whole section from the end of chapter 5, to the beginning of the Noah story in chapter 6, verse 9, is setting up the flood that is coming. Genesis wants us to see that the global flood of God’s wrath is not random or haphazard. It is warranted.

The question that will help guide us, and that these verses serve to answer is, Why did God flood the world? These verses provide at least three answers, and we’ll get to the Nephilim under the third one.

1. The Great Wickedness of Human Hearts (verse 5)

Verse 5: The Lord saw that the wickedness of man was great in the earth, and that every intention of the thoughts of his heart was only evil continually.

As we’ve seen, Adam and Eve rebelled against God. Cain killed Abel. Cain’s line, even with its cultural and technological advances, spiraled downward in increasing sin. And a global flood is no exaggerated response to such rebellion. Human wickedness is growing, and deepening — “every intention of the thoughts of his heart was only evil continually.” Every intention, only evil continually. In other words, great and total. Man’s sin and rebellion are not small, but great. And not partial, but total.

Genesis 6:5 gives us our first glimpse in the Bible of what we call “total depravity.” Total depravity means that our sin is so great and so deep that we are unable to free ourselves from it. We are totally unable to save ourselves. Total depravity doesn’t mean that all humans are as bad as they could be, but that there are no parts of us unaffected by sin, and no way for us to rescue ourselves. We are beyond self-help, which is very offense to hear today in our society centered on self.

But you might ask, Is this still true about humans today? All these people in Genesis 6, except for Noah, were wiped out by the flood. There’s a new start for the human race. Surely, this “total depravity” has been left behind, washed away in the flood.

Turn over the page to Genesis 8:21, and God’s promise after the flood. “I will never again curse the ground because of man, for the intention of man’s heart is evil from his youth.” No, total depravity is not gone with the flood. It came into the ark with Noah and his family, and we’ll see evidence of that when we get to Genesis 9. And then throughout the Bible, we hear:

  • Psalm 51:5: “Behold, I was brought forth in iniquity, and in sin did my mother conceive me.”

  • Jeremiah 17:9: “The heart is deceitful above all things, and desperately sick; who can understand it?”

  • Romans 3:9–11: “All . . . are under sin, as it is written: ‘None is righteous, no, not one; no one understands; no one seeks for God. All have turned aside; together they have become worthless; no one does good, not even one.’”

  • Romans 7:18: “I know that nothing good dwells in me, that is, in my flesh.”

And perhaps the passage that best gets at the heart of what total depravity is — Romans 8:7–8: “The mind that is set on the flesh is hostile to God, for it does not submit to God’s law; indeed, it cannot. Those who are in the flesh cannot please God.”

So, Genesis 6:5 gives us one reason why the flood came — because of the greatness of human wickedness. And it also tells us something vitally important about ourselves — that we should not underestimate the evil in our hearts apart from the help of God’s Spirit.

So, the first reason God flooded the world was the great wickedness of human hearts.

2. The Great Grief of God’s Own Heart (verses 6–7)

Verses 6–7: And the Lord regretted that he had made man on the earth, and it grieved him to his heart. 7 So the Lord said, “I will blot out man whom I have created from the face of the land, man and animals and creeping things and birds of the heavens, for I am sorry that I have made them.”

Human sin grieves God. This is a very important point not to miss, and very easy to miss, because in our sin, we are so prone to take sin lightly — both in ourselves and in others. We know God is big and gracious, and we may begin to believe the lie that my little sins don’t matter at all the time. Even if God notices, he’s ready to forgive. That’s his job.

But that sort of light treatment of sin reflects a tragic lack in the knowledge of God. To know the heart of God is to know the grievousness of sin. Those who know God cannot be cavalier about sin, because he is not (whether it’s excusing our own or condoning the sins of others). He is not indifferent to human sin. To take sin lightly is to take God lightly.

So far, we have a very bleak picture — humanity depraved and God grieved — and as we move to verses 1–4, and ask about the Nephilim, it’s not getting any brighter. Not yet. But there is a ray of hope in verse 8 I want us to catch and carry with us back to verses 1–4.

Noah Found Grace

In the midst of a falling and failing human race, with minds set on the flesh, hostile to God, and God grieved by the deep rebellion of his creatures, verse 8 reads: “But Noah found favor in the eyes of the Lord.” In these dark clouds of Genesis 6:1–7, a lightning bolt of grace flashes in verse 8.

Note that “favor” comes to Noah before anything is said about his good conduct:

  • First, verse 8: “Noah found favor in the eyes of the Lord.”

  • Then, verse 9: “Noah was a righteous man, blameless in his generation. Noah walked with God.”

We shouldn’t make too much of the ordering here, but we also shouldn’t overlook it.

Another way to translate “favor” here is “grace.” This is the first mention of grace in the Bible. And given what we learn about grace in the rest of the Bible, I doubt it’s insignificant that Genesis leads with God’s grace, and then mentions Noah’s righteous life. Not the other way around. Grace came first and empowered a life of righteousness, not righteousness came first and earned the reward of favor. First, God’s favor, then holy behavior.

From Noah’s Birth to Noah’s Ark

Now, at last, we come to verses 1–4, to find out what is going on between this first mention of Noah at the end of chapter 5 and the return to Noah in 6:8. We need to begin by seeing that this is all one section. The break between chapter 5 and 6 in our English Bibles may throw us off. Genesis 6:1 is not the beginning of a new section, but continues the flow of chapter 5. Noah was just introduced at the end of chapter 5, and Noah will be reintroduced in 6:8–9.

What verses 1–7 do is answer the question what happened between the high hopes of Noah’s birth (5:28–29) and the rising flood waters? How did the godly line catalogued in chapter 5 lead to the destruction of the world through a global flood? That’s how verses 1–4 answer our question about why God flooded the world.

3. The Great Compromise of God’s People (verses 1–4)

There is a great compromise here, and highlighting it is one way of getting at the reasons for the great flood. To explain what the great compromise is, let’s finish by answering three questions:

Who are “the sons of God” in verse 2? Who are “the Nephilim” in verse 4? What does it mean for us today?

First, who are “the sons of God”?

“The sons of God” may land on us as a surprising phrase, especially if we are just opening up our Bibles to the beginning of chapter 6 and haven’t caught the flow of chapters 4 and 5.

What Genesis has been doing in chapters 4 and 5 — going back to the curse of the serpent in Genesis 3:15 — is setting up a tale of two cities: the city of man and the city of God. This is, in a sense, the great story of all of history: the story of two “offsprings.” Remember what God said to the serpent in Genesis 3:15:

“I will put enmity between you and the woman, and between your offspring and her offspring; he shall bruise your head, and you shall bruise his heel.”

What we saw last week was that Eve thought she “got” her offspring with Cain. But chapter 4 shows us that Cain actually becomes the offspring of the serpent, like the rest of mankind (Ephesians 2:1–3; 2 Corinthians 4:4). Sin crouches at his door, desires to consume him, and he does not rule over sin, but rather is ruled by the serpent (Genesis 4:7).

Then after we get the genealogy of Cain (Genesis 4:17–24), the city of man, God “starts again,” so to speak, in chapter 5. Instead of a son “gotten,” a son is “given.” His name is Seth. Eve had said at the birth of Cain in 4:1, “I have gotten a man,” but in 4:25 she says offspring: “God has appointed for me another offspring instead of Abel.”

Cain’s line in chapter 4:17–24 is the line of man, the first house of Adam, which becomes the offspring of the serpent. And Seth’s line in chapter 5 is Adam’s second house. We saw last week how “an alternative history” begins to unfold in chapter 5. This is the godly line, the sons of God, the line of promise. As man begins to multiply in the earth, God appoints a godly line. So chapter 5 ends on a high note: Noah, a son of great promise, in the godly line, is born. Then Genesis 6:1–4 comes in to explain to how we got from this high note of promise to the low note of human depravity in Genesis 6:5. The answer is the great compromise.

When we come to Genesis 6:1, with chapters 4 and 5 in view, it shouldn’t be a big surprise to us who “the sons of God” are. This is the godly line that just unfolded in chapter 5. These are God’s special people in the midst of the corrupt and depraved humanity of chapter 4. Genesis 6:1 takes us back to “when man began to multiply on the face of the land and daughters [not sons!] were born to them” — that’s chapter 4, and then gives us this tragedy in verse 2: “the sons of God saw that the daughters of man were attractive. And they took as their wives any they chose.”

This is the compromise of the godly line with the ungodly rest of humanity. “The sons of God,” the special people of God who traced their descent to Seth, the given son, appointed by God — God’s people compromised. Just like Eve “saw that the tree was good” and “took” (Genesis 3:6), so now the sons of God “saw that the daughters of man were attractive” (same word as good) and “took as their wives” (Genesis 6:2). In other words, just as Eve disobeyed God’s law and ate the forbidden fruit, so God’s specially appointed people neglected God’s calling and took forbidden wives.

So, to put it as clearly as I can for you, in answer to our first question, “the sons of God” in verse 6 is the line of Seth just developed in chapter 5.


Now I said at the beginning that some Christians think these “sons of God” are angels. Later on in the Bible, the phrase “sons of God” does refer to angels at times (as in Deuteronomy 32:8; Job 1:6; 2:1; 38:7).

In addition to reading “sons of God” within the context of Genesis 4 and 5, here are a few other brief reasons why it seems highly unlikely that “sons of God” here means angels:

  • “Sons of God” doesn’t mean angels till much later in the Bible; and the phrase does not mean angels every time it’s used (besides, the original readers didn’t have the rest of the Scripture to compare; they had to read it in context)

  • This intermarriage of “sons of God” with “daughters of man” is part of what is given as reason for the flood, which punished humans, not angels. It doesn’t make sense for God to punish man for angels’ sin.

  • Genesis 1 emphasizes (ten times) how everything in God’s creation reproduces after its kind; humans reproduce with humans, not angels

  • Angels are spirit beings, not material; being seen, by special provision, is one thing; being touched is another; having reproductive organs, quite another; and another still taking and keeping a human wife (verse 2, “took as their wives” is a typical phrase for marriage, not rape or assault, but actually taking, and keeping, as a wife)

  • Nothing we know about angels anywhere else in the Bible inclines us to think that there’s any real possibility that they could marry and procreate with humans (Matthew 22:30; Mark 12:25; Luke 20:34–36 actually says “in the resurrection they neither marry nor are given in marriage, but are like angels in heaven”; that doesn’t necessarily say anything about angelic reproductive organs, but it does say expressly the opposite of what Genesis 6 says, that angels do not marry).

“The sons of God,” then, are not angels, but the godly line of chapter 5, and “the daughters of man” are women from the rest of mankind. But what’s not nearly as clear to me is our second question, “Who are the Nephilim?”

Second, who are the Nephilim?

By ruling out that “the sons of God” are not angels, we at least rule out one popular interpretation, that the Nephilim are angelic-human hybrids. But who are these mysterious Nephilim, then? I can’t give you a confident answer, but I think I can point us to some good options.

It is important to note that the text does not say that the Nephilim are the offspring of the intermarriage of the godly line with the rest of humanity. Verse 4 comes in, not to explain who “the sons of God” are, or what the offspring of the sons of God and daughters of man are, but almost as an aside.

The Nephilim were on the earth in those days, and also afterward, when the sons of God came in to the daughters of man and they bore children to them.

It does not say the Nephilim were on the earth because the sons of God came in to the daughters of man, but when. The question to ask, then, is why mention the Nephilim? What purpose does verse 4 serve? Does it contribute somehow to the wickedness that brought about the flood?


Many people have speculated that the Nephilim were giants — some have thought angel-human hybrids who were giants — but just as we saw how angels is not a likely interpretation, so also “giants” is unlikely. It is true that the word “Nephilim” appears again in Numbers 13:32–33, when the Israelite spies bring the back the bad report:

The land, through which we have gone to spy it out, is a land that devours its inhabitants, and all the people that we saw in it are of great height. 33 And there we saw the Nephilim (the sons of Anak, who come from the Nephilim), and we seemed to ourselves like grasshoppers, and so we seemed to them.”

Here Nephilim is associated with people of great height, but it doesn’t say that the people are of great height because they are Nephilim. First, they see “people . . . of great height”; then, it says, “And there we saw the Nephilim.” At most we can say that the spies saw what they characterize as Nephilim in a land of people with great height, but that does not mean that the word Nephilim necessary means great height or giant.

But Genesis 6:4 does have something to say for us about what Nephilim means in the last part of the verse: “These were the mighty men who were of old, the men of renown.”

So the Nephilim are not said to be giants, but to be “mighty men,” which goes well with the literal meaning, “those who fall” — as well as “men of renown,” or literally, “men of fame.” Who are they then? Perhaps the original readers knew, and it’s just been lost to us. But I see two possibilities in this text: one positive, one negative.

If the Nephilim are positive (godly), then perhaps they are the “men of name” in chapter 5. Chapter 5 has just mentioned nine “men of name” from Seth to Noah. The sons of God, then, would be their whole line and all the offspring, while the Nephilim are the men of name from within the line.

But as best as I can tell — and again, this is so far from certain — the context makes me tip toward a negative, not positive (but evil), meaning for the Nephilim, as warriors, “mighty men.” They are perpetrators of violence. This would help explain the repeated language of corruption and violence in verses 11–13. And this probably fits best with the whole flow of 6:1–7 pointing to the compromise of the godly line, and human wickedness, and God’s grief over it all. Perhaps the Nephilim as “men of name” are the names from chapter 4 and Cain’s line.

Third, what do we learn from verses 1–4?

Of the many lessons we could draw, let me just mention one: Let this be a warning to us, as the new-covenant people of God (“the sons of God”), not to forsake our calling by making compromising commitments with the city of man. Clearly that means marriage, that a son or daughter of God should not enter into a marriage covenant with a mere son or daughter of man. The Scriptures recapitulate the tragedy of God’s people being unequalled yoked in marriage with unbelievers over and over again. Paul reiterates it in the New Testament (1 Corinthians 7:39; 2 Corinthians 6:14).

However, I think there are implications beyond just the covenant of marriage to all sorts of compromising commitments we can make with the world.

As the sons of God, we need to be careful whom we commit ourselves to: what brands, or organizations, or groups, or political parties, or particular candidates. In recent months, too many well-known Christians, who surely would think of themselves as “sons of God,” have leveraged their influential capital, amassed in gospel ministry, to publically endorse (commit to) a presidential candidate. They may have thought that by committing to him or her, they could perhaps influence that flawed candidate to be more godly. But the opposite has been the case. Compromising commitments do not empower the godly to pull the ungodly up, but the ungodly to bring down the godly. As Christians, as the sons of God, we should take great caution to whom we declare our allegiance. The children of light do not make deals with the darkness.

Our calling as the sons of God isn’t that we remove ourselves from the world, but that we engage in love with our corrupt world in such a way that we shine light into the darkness, not have our light diminished, or put out, by the darkness. We want to win our unbelieving society, but that doesn’t come through compromising commitments, but through acts of love and articulating the gospel.

To the Table

As we come to the Table, we are reminded that God has not left it up to us to keep ourselves from compromise with the unbelieving world, but he has given us his Spirit.

Verse 3: “My Spirit shall not abide in man forever, for he is flesh.” But for those of us who are in Christ, the capital-S Son of God, God’s Spirit is with us to help us.

God removed his Spirit of blessing, and the “sons of God” in Genesis 6 did not preserve their purity as God’s people, but God gives us his Spirit to preserve the purity of his people. And one way that he does that is by feeding our souls and nurturing our bond with Christ through receiving his grace, by faith, here at the Table.