Satan in the Bible: Comparing the Devil in the Old & New Testaments

Disclaimer: The views and opinions expressed in this article belong to the author and do not necessarily match my own. - Dr. Bart D. Ehrman

Is Satan real? Research would at least suggest that many people consider this figure an important part of their beliefs and perspectives. A recent Pew Research Center survey found that 44% of U.S. adults say the statement “Satan is responsible for most of the suffering in the world” describes their views either “very well” or “somewhat well.” 

The same survey showed significant differences across religious traditions: evangelical Protestants and members of historically Black Protestant churches were especially likely to affirm this view, while Catholics and mainline Protestants were less likely to do so. 

Still, whatever the differences between Christian denominations, the broader point is striking. Is the Devil real? To a substantial number of people today, yes. Satan isn’t merely a symbol, metaphor, or fictional figure from horror films. He is understood as a real supernatural being whose activity helps explain the evil and suffering we see in the world. 

That contemporary belief gives us a good reason to step back and ask a historical question: where did this idea of Satan come from?

Many modern readers assume that the Bible presents one consistent portrait of the Devil from beginning to end: the enemy of God, the tempter of Adam and Eve, the ruler of demons, and the source of evil in the world. 

But when we read the biblical texts carefully and historically, the picture turns out to be more complicated. The figure later known as “the Devil” didn’t appear all at once in a fully developed form.

Instead, the biblical traditions preserve traces of a development, with different texts imagining “Satan” in different ways.

This article will explore that development by comparing the figure of Satan in the Old and New Testaments. 

We’ll begin with the meaning of the word “Satan” itself, since its original sense is crucial for understanding the earliest texts. 

We’ll then look at the Hebrew Bible, where Satan is often better understood as an adversary, accuser, or tester than as the cosmic enemy familiar from later Christian theology.

From there, we’ll turn to the New Testament, where Satan emerges much more clearly as the personal opponent of God’s kingdom, the tempter of Jesus, and the ruler of demonic forces.

Finally, we will briefly consider how mainstream Islam preserves and reshapes related traditions through the figures of Iblīs and al-Shayṭān.

Who Is the Devil? The Etymology of the Term “Satan”

In the Dictionary of Deities and Demons in the Bible, Cilliers Breytenbach explains:

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That linguistic point is crucial for understanding the history of Satan in the Bible. In modern English, “Satan” usually functions as a proper name (pronunciation: SAY-tuhn): the name of the Devil, God’s supernatural enemy. 

But the Hebrew term originally describes a role or function rather than necessarily identifying one specific evil being. A śāṭān is someone who opposes, obstructs, challenges, or accuses. 

Depending on the context, that adversary may be a human opponent, a legal accuser, or a heavenly being who plays an adversarial role.

As Elaine Pagels notes in her book The Origin of Satan:

This means that the history of Satan isn’t simply the history of one fixed character appearing unchanged from Genesis to Revelation.

It’s the history of how a common noun meaning “adversary” or “accuser” gradually came to be associated with a particular supernatural figure. To see that development more clearly, we need to turn first to the Old Testament itself, where “Satan” often appears in ways quite different from the Devil familiar to later Christian imagination.

Satan in the Old Testament: Accuser, Adversary, and Tester

In the preface of his classic study The Devil: Perceptions of Evil from Antiquity to Primitive Christianity, Jeffrey B. Russell notes:

That is precisely the kind of historical question we need to ask here. Not “Does Satan exist?” but rather: Who is Satan? Or, more precisely, who is Satan in the Hebrew Bible? 

If by “biblically accurate Satan,” we mean the Satan most familiar from later Christian theology (the Devil, the enemy of God, ruler of demons, and cosmic source of evil), then the answer is surprising: that figure is largely absent from the Old Testament.

The first thing to notice is that the Hebrew Bible uses śāṭān in a variety of ways, and not all of them refer to a supernatural being. Sometimes the word simply means a human adversary or opponent. 

In 1 Samuel 29:4, for example, the Philistines worry that David might become their śāṭān, that is, their adversary.

In 1 Kings 11:14, Hadad the Edomite is described as an adversary raised up against Solomon. Similar usage appears elsewhere, showing that śāṭān could function as an ordinary noun for someone who opposes another person politically, militarily, or legally.

This is important because it means that the word didn’t begin as the personal name of the Devil. It described a role: an adversary, opponent, or accuser.

Even when śāṭān refers to a heavenly being, the figure isn’t yet the Devil of later imagination. In Numbers 22:22–35, the angel of the LORD stands in Balaam’s path “as an adversary”: as a satan.

But this heavenly figure isn’t rebelling against God. Quite the opposite: he acts as God’s messenger, blocking Balaam’s way because Balaam’s journey has incurred divine anger.

In this story, then, the supernatural satan is an agent of God, not God’s archenemy. The same caution is needed in Zechariah 3:1–2, where “the satan” stands at the right hand of Joshua the high priest to accuse him. 

The scene is juridical, almost like a heavenly courtroom. The satan accuses; the LORD rebukes him; Joshua is vindicated. But even here, the word appears with the definite article (“the satan”)  suggesting a role or function rather than a proper name. He is an accuser in the divine court, not yet the ruler of an evil kingdom or realm.

The most famous Old Testament appearance of “the satan” comes in Job 1–2. There, the sons of God present themselves before the LORD, and “the satan” appears among them. 

Again, the setting is the divine council, not a battlefield between equal cosmic powers. The satan questions Job’s piety: does Job serve God for nothing, or only because God has blessed and protected him?

His role is adversarial, but it’s also theological. He challenges the moral logic of the world in which righteousness is rewarded with prosperity. 

Yet he doesn’t act independently. He must receive God’s permission before testing Job. This is why the Book of Job is so important for understanding Satan in the Hebrew Bible: it shows a heavenly accuser or tester, but not an autonomous principle of evil opposed to God.

Another especially revealing text is 1 Chronicles 21:1, where Satan incites David to take a census of Israel.

This passage is striking because it parallels 2 Samuel 24:1, where it is the anger of the LORD that incites David to take the census.

The Chronicler’s version appears to shift the immediate cause from God to Satan. Many scholars, Russell included, have seen this as an important moment in the development of biblical thinking about evil: a later writer seems less willing to attribute a morally troubling action directly to God and instead assigns the role to Satan. 

Even so, we shouldn’t overstate the point. The Hebrew Bible still doesn’t present Satan as a fully independent enemy of God. 

Rather, it gives us several related images (human adversary, divine messenger, heavenly accuser, tester, and possible instigator) that later Jewish and Christian traditions would develop much further.

To see that fuller development, we must now turn to the New Testament, where Satan appears in a far more dramatic and cosmic role.

Satan in the Bible: The New Testament Evidence

In his book Satan: A Biography, Henry Ansgar Kelly notes:

This is a fitting place to begin because the instances where Satan tempts Jesus in Matthew 4:1-11 and Luke 4:1-13 already reveal a major shift from the Hebrew Bible.

Satan is still a tester, but now the testing takes place within a much larger cosmic drama. Jesus isn’t simply another righteous person whose loyalty is examined. He is the bearer of God’s kingdom, and Satan appears as the one who seeks to divert that mission from the beginning.

In the New Testament, therefore, the concept of Satan is far more developed than it’s in the Hebrew Bible. 

The figure who appeared only occasionally as an adversary or accuser now becomes a central opponent in the story of salvation. 

As Russell puts it, the New Testament Satan is best understood in relation to Christ: he is the “counterpart” or “counterprinciple” to Christ, because the Kingdom of God is portrayed as being at war with the kingdom of the Devil. 

The New Testament doesn’t present Satan as God’s equal, but it does portray him as a powerful, personal, supernatural opponent whose influence extends through demons, temptation, deception, illness, and opposition to the gospel. 

In this sense, the New Testament moves much closer to an apocalyptic worldview in which the present age is marked by conflict between God’s reign and the powers of evil (see the “Did You Know?” box). 

Russell’s excerpt emphasizes precisely this point: Satan isn’t peripheral to the New Testament imagination but belongs to its way of explaining why the world remains under the power of evil even as God’s saving action is breaking into history.

This cosmic conflict is especially visible in the Synoptic Gospels. In Mark 3:22–27, Jesus’ opponents accuse him of casting out demons by the power of Beelzebul, “the ruler of the demons.” 

Jesus responds that Satan cannot cast out Satan; if Satan’s kingdom is divided, it cannot stand. He then compares his ministry to entering a strong man’s house, binding him, and plundering his property. 

The implication is clear: Jesus’ exorcisms are signs that Satan’s rule is being challenged and overthrown. 

Matthew 12:28 and Luke 11:20 make the point even more explicitly: if Jesus casts out demons by the Spirit or finger of God, then the kingdom of God has arrived. 

The Dictionary of Deities and Demons in the Bible summarizes this New Testament pattern well: Satan is depicted as Jesus’ major opponent, identified with Beelzebul in the Synoptic tradition, and defeated through Jesus’ exorcisms and healings.

The same development appears in other New Testament writings, though with different emphases. 

In Paul, Satan can obstruct missionary work, as in 1 Thessalonians 2:18, where Paul says that “Satan blocked our way.” He can disguise himself “as an angel of light” in 2 Corinthians 11:14. 

He can be associated with affliction, temptation, and exclusion from the community, as in 2 Corinthians 12:7 and 1 Corinthians 5:5. 

In Acts 26:18, Paul’s mission is described as turning people “from darkness to light and from the power of Satan to God.” 

Paul can even speak of Satan, or a Satan-like power, as “the god of this world” who blinds the minds of unbelievers (2 Corinthians 4:4), a phrase that shows just how strongly some early Christians imagined the present age as being under the influence of hostile spiritual powers.

These texts do not give us a systematic doctrine of Satan, but they show how widely the figure had come to function as the personal power behind deception, opposition, sin, and estrangement from God. 

In other words, Satan isn’t merely an accuser in a heavenly court anymore. Rather, he is a force active in human communities and in the mission of the early church.

The Gospel of John and the book of Revelation push the imagery still further. In John 12:31, Satan is called “the ruler of this world,” and in John 8:44, he is described as a murderer and liar. Revelation gives the most dramatic portrait of all. 

In Revelation 12:9, Satan is identified as “the great dragon,” “that ancient serpent,” “the Devil,” and “the deceiver of the whole world.” 

Revelation 20:2 repeats this identification and looks ahead to his final defeat. This is crucial for understanding the later Christian imagination: the explicit identification of Satan with the serpent of Genesis isn’t made in Genesis itself but appears in later interpretive traditions, especially in texts such as Revelation. 

Yet even here, the New Testament doesn’t quite present the fully medieval Satan who rules hell as its king and tortures the damned. As Russell notes, that later image belongs to subsequent Christian development. The New Testament Satan is powerful, dangerous, and deceptive, but he is also temporary. His power belongs to “this age,” and his defeat is already anticipated.

The New Testament, then, offers a much more developed portrait of Satan than the Hebrew Bible, but it still does not collapse into absolute dualism. 

Satan is the tempter of Jesus, the ruler of demons, the deceiver of humanity, the opponent of the gospel, and the power behind the kingdom of darkness. 

The New Testament also contains passages that associate him with fallen heavenly powers (most dramatically in Revelation, where Satan is cast down from heaven), though the familiar image of Satan as the supreme fallen angel was developed more fully in later Christian tradition.

Yet he isn’t equal to God, and his rule is neither ultimate nor eternal. The central New Testament claim (especially visible in later NT Gospels!) is that the kingdom of God has already begun to defeat the kingdom of Satan through the ministry, death, and resurrection of Jesus.

That Christian development of the figure of Satan would become enormously influential. But before concluding, we should briefly turn to another major Abrahamic tradition and ask how mainstream Islam understood and reshaped the related figure of Iblīs, or al-Shayṭān.

Satan in the Islamic Tradition

In his book What Everyone Needs to Know About Islam, John L. Esposito notes:

So, Islam also shares a concept of Satan that, as Bernard Lewis explains in his book Islam: The Religion and the People, “appears frequently in the Koran, especially in the role of tempter, as for example in the final chapter (114) in which the believer is urged ‘to seek refuge with God from the evil of the insidious tempter, who whispers in the hearts of men’.”

The Quranic figure most closely corresponding to Satan is Iblīs, who is also associated with al-Shayṭān, “the Satan” or “the Devil.” 

His central story appears in several Quranic passages: God commands the angels to bow before Adam, and all obey except Iblīs. The Qur’an explains his refusal as an act of pride: he considers himself superior because he was created from fire, while Adam was created from clay.

In Q 18:50, Iblīs is explicitly described as “one of the jinn,” and his refusal is presented as rebellion against God’s command.

This is one of the major differences from much Christian tradition: mainstream Islam generally doesn’t understand Satan as a fallen angel in the strict sense, since angels are usually viewed as obedient servants of God.

Rather, Iblīs is commonly understood as a jinn, a created being with the capacity to obey or disobey.

Theologically, however, Iblīs isn’t God’s equal, rival, or independent cosmic principle. Islam is radically monotheistic, and Satan’s power remains limited and derivative. 

After his refusal to bow, Iblīs asks for a reprieve until the Day of Judgment and is permitted to tempt human beings. 

His role, therefore, is primarily that of a tempter and deceiver. He “whispers” evil suggestions into human hearts, but he cannot compel people to sin. 

The moral burden remains on human beings, who are responsible for whether they follow divine guidance or yield to satanic temptation. This is why the Islamic picture of Satan is close to the New Testament in seeing Satan as an active tempter, but close to biblical monotheism more broadly in refusing to make him an independent power alongside God.

In comparative terms, then, Islam preserves and reshapes several elements familiar from Jewish and Christian traditions. Like the New Testament Satan, Iblīs is a personal tempter who seeks to lead humanity away from God.

Like the Satan of the Hebrew Bible, however, he remains firmly under divine sovereignty and never becomes God’s metaphysical opposite.

His story is ultimately a warning about arrogance, disobedience, and moral accountability. With that broader Abrahamic comparison in view, we can now return to the central question of the article: how did Satan move from adversary and accuser to one of the most powerful symbols of evil in Western religious imagination?

Conclusion: From Adversary to Devil

How, then, did Satan move from the relatively limited figure we find in the Hebrew Bible to the cosmic enemy of God and humanity in the New Testament? 

The crucial bridge is Jewish apocalypticism, a form of Jewish thought that became especially prominent during the Second Temple period, beginning roughly in the third and second centuries B.C.E. 

Apocalyptic Jews were wrestling with a painful historical question: if God is sovereign, why do foreign empires, wicked rulers, and violent oppressors continue to dominate God’s people? Their answer wasn’t that God had lost control, but that the present world had temporarily fallen under the power of hostile supernatural forces. 

History, in this view, was moving toward a dramatic divine intervention in which God would defeat evil, judge the wicked, and vindicate the righteous.

Bart Ehrman, in his book Heaven and Hell, explains this clearly:

That transformation is the key to understanding the difference between the Old and New Testaments.

In the Hebrew Bible, Satan is usually not the Devil in the later sense. The word, as we saw, can mean an adversary, an opponent, or an accuser; even when it refers to a heavenly being, that figure remains subordinate to God.

But in Jewish apocalyptic thought, the problem of evil came to be imagined on a much larger cosmic scale. Evil was not only the result of human wrongdoing.

It was also connected with rebellious spiritual powers that opposed God’s people and corrupted the present age. By the time we reach the New Testament, this apocalyptic framework has become central: Satan is now the tempter of Jesus, the ruler of demons, the deceiver of humanity, and the power behind the kingdom of darkness.

Finally, the history of Satan is, in its essence, a history of how Jews, Christians, and Muslims have tried to answer one of the oldest questions human beings have asked: why is there evil, and how does it stand against the purposes of God? 

Later Christian imagination would develop the figure even further: Satan became the horned ruler of hell in medieval art, father of lies, the proud rebel of later literary tradition, and eventually, a figure known as Lucifer invoked in modern discussions of Satanism.

But these later developments shouldn’t be read back directly into the Bible. The biblical story is more complex and historically layered!