Soul vs Spirit: What's the Difference?

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

How should we understand the difference between soul vs. spirit? According to one recent study, more than eight in ten Americans believe that human beings have a soul or spirit (83%), while 81% say that there is something spiritual beyond the natural world, even if it cannot be seen.

Such figures suggest that belief in some non-material dimension of human existence remains remarkably widespread even in the modern world.

Yet they leave a more fundamental question unanswered: where did these ideas come from? Like most concepts that have survived for centuries, “soul” and “spirit” didn’t emerge with fixed meanings. Both have long and complicated histories, shaped by different philosophical, religious, and cultural traditions.

To understand why the two terms sometimes overlap and at other times seem to describe different aspects of human existence, we need to trace that history.

In the ancient Greek world, philosophers (most famously Plato) developed influential ideas about the soul, its relationship to the body, and its possible survival after death. 

Early Christians inherited this philosophical vocabulary, but they also drew upon Jewish traditions and their own experiences of God’s Spirit. The New Testament therefore uses the Greek words psychē (“soul”) and pneuma (“spirit”) in ways that are related but not always identical.

This becomes especially intriguing in Paul’s First Letter to the Thessalonians, where he refers to a person’s “spirit and soul and body” in the same sentence. What is the difference between soul and spirit to Paul, and what distinction, if any, did he intend to convey? And how did later Christians understand these categories? 

Following these questions from Greek philosophy through Paul and into early Christianity reveals that the definitions of soul and spirit were never quite as simple as it might first appear.

If you are really interested in the life of the apostle Paul and his views on women, check out Travis Proctor’s 4-lecture course, Must Women Keep Silent? Paul’s Real Views on Gender, Desire, and Women. 

It explores the tensions within Paul’s authentic letters, from women serving as deacons and apostles to debates over marriage, veiling, desire, and speaking in church, while also tracing how later Christians used Paul’s name to support sharply different views of women and authority.

Soul and Spirit Before Christianity: From Psychē to Plato

In his book The Discovery of the Mind, Bruno Snell notes:

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In other words, the Greek concept of the psychē (the word usually translated as “soul”) didn’t begin with the rich psychological and philosophical meaning that it would later acquire. 

In early Greek poetry, it was primarily connected with life and with what departed from a person at death. The idea that the soul was the rational and moral center of an individual developed only gradually.

By the time of Plato in the 4th century B.C.E., however, we see a considerable development in ideas concerning the soul and what we might call the “spirited” dimension of human beings. 

The immortality of the psychē became one of Plato’s recurring concerns. In the Phaedo, for example, Socrates argues that the soul is the bearer of life: just as fire necessarily brings heat, the soul brings life to the body. 

Because death is the opposite of life, Plato reasons that the soul cannot itself admit death. When the body dies, therefore, the soul doesn’t simply perish with it, but leaves the body and continues its existence.

This conviction had important ethical consequences. Human life could no longer be evaluated solely within the boundaries between birth and death; the condition of the soul and the way a person lived had consequences extending beyond a single bodily existence.

For Plato, however, the soul was much more than something that happened to survive the death of the body. 

It increasingly became the center of rationality, moral character, and personal identity. As Michael Erler emphasizes, Plato’s ideal of philosophy was closely connected with the epimeleia tēs psychēs, the “care of the soul.”

The philosopher sought to cultivate reason and prevent bodily desires and disruptive emotions from controlling judgment. This is precisely how Plato portrays Socrates in the Phaedo: confronted with his own execution, Socrates remains calm because he trusts rational argument and regards his true self not simply as the mortal body that is about to die, but as the rational soul that survives it.

Plato’s picture of the soul also became more complicated over time.

In the Republic, he famously distinguishes three aspects of the psychē: the rational part, the appetitive part, and a third element usually called the “spirited” part, or thymos.

The spirited element includes impulses connected with anger, ambition, courage, and the desire for recognition; ideally, it supports reason in governing the appetites. 

Here, however, an important distinction is necessary! 

Plato’s “spirited” element isn’t pneuma, the Greek term that would later become especially important in early Christian discussions of the “spirit.” 

It’s instead one component within the psychē itself. Plato’s later works further complicate matters by associating immortality most strongly with the rational component of the soul. In the Timaeus, for example, the intellect is immortal, while appetite and the spirited element are mortal.

Spirit vs. soul discussions within Greek philosophy therefore provided later thinkers with an increasingly sophisticated vocabulary for discussing what makes human beings alive, rational, morally responsible, and capable of existing beyond bodily death.

Yet the categories inherited by early Christians weren’t simply Platonic ones, and the Greek word pneuma would acquire particular importance in Jewish and Christian contexts.

To see how “soul” and “spirit” could function together (and sometimes be distinguished) we can now turn to one of our earliest “Christian” authors, the apostle Paul.

Soul and Spirit in Paul: What Does 1 Thessalonians 5:23 Mean?

In his groundbreaking study The Corinthian Body, Dale Martin notes:

Martin’s point is important because it warns us against assuming that Paul used words such as “soul,” “spirit,” “mind,” and “body” as neatly separated philosophical categories. 

His language emerged from a complex interaction between Jewish apocalyptic expectations, Greco-Roman ideas about the human person, and his conviction that God’s Spirit was already transforming believers.

Nowhere is the soul vs. spirit distinction more explicitly mentioned than in what is generally regarded as Paul’s earliest surviving letter, 1 Thessalonians. 

Near the end of the letter Paul prays:

At first sight, the wording seems remarkably precise. Paul names pneuma (“spirit”), psychē (“soul”), and sōma (“body”) separately, apparently presenting three components of the human being. 

It’s therefore understandable that some later (“Gnostic-like”) interpreters have treated this verse as evidence for a tripartite anthropology: a human person composed of body, soul, and spirit. 

Yet the literary context strongly cautions against reading the verse as though Paul were offering a systematic philosophical definition of human nature.

Leon Morris, in his Commentary on 1 Thessalonians, emphasizes precisely this point. Paul has just completed a series of exhortations concerning Christian conduct (living peacefully, supporting the weak, praying, giving thanks, remaining receptive to the Spirit, testing prophecy, and avoiding evil) and he now turns those exhortations into a prayer. 

Morris argues that the transition is significant: Paul has told the Thessalonians how they should live, but he now acknowledges that only God can finally bring their sanctification to completion. 

The controlling idea in verse 23 is therefore not the internal anatomy of the human person but completeness. Paul prays that God will sanctify them “through and through” and that the whole person will be preserved blameless until Christ’s coming. 

The sequence “spirit, soul, and body” is best understood within that rhetorical aim: every dimension of their existence is to belong to God.

This doesn’t mean that Paul regarded psychē and pneuma as meaningless synonyms. Elsewhere, he can use the terms differently, and pneuma, in particular, has enormous theological importance for him because it can refer either to the human spirit or, far more commonly in certain contexts, to the Spirit of God.

Indeed, only a few verses before 5:23, he tells the Thessalonians, “Do not quench the Spirit,” where the reference is clearly to divine activity in the Christian community. 

But 1 Thessalonians 5:23 doesn’t allow us to draw a rigid difference between soul and spirit as though Paul were defining two independently existing substances. 

Morris observes that Paul is praying rather than “giving a theoretical description of the nature of the human constitution.” He compares this language with passages that speak simply of “body and spirit” or, in another context, of “heart, soul, mind, and strength.” 

Such lists are better understood as ways of expressing the totality of the person than as metaphysical diagrams.

Paul’s inclusion of the body is especially revealing. 

Whatever influence Greek philosophical language may have exercised on his vocabulary, Paul doesn’t imagine salvation as the final escape of an immortal soul from a disposable body.

His apocalyptic hope centers on resurrection, and, therefore, bodily existence remains integral to the human person.

Morris highlights precisely this contrast: where some Greek traditions could regard the body as a prison or tomb of the soul, Paul’s theology insists that full human existence cannot simply dispense with embodiment. 

In the generations that followed, Paul’s name carried enormous authority and inspiration. 

Different early Christian authors and teachers found very different things in his theology: from Valentinian Christians whose views contemporary scholars sometimes associate with forms of “Gnosticism” to bishops and theologians who increasingly presented themselves as guardians of what came to be known as Christian “orthodoxy.” 

Their attempts to explain soul, spirit, body, and salvation would therefore take Paul’s language in strikingly different directions. Let’s take a look at one key example!

How Early Christians Made Sense of the Distinction: Irenaeus

In his book Remembering Paul, Benjamin White notes:

One of the earliest Christian authors who remembered and interpreted Paul in a particularly influential way was Irenaeus, bishop of Lyon at the end of the 2nd century. 

For the purposes of the present discussion, his brief interpretation of 1 Thessalonians 5:23 in Against Heresies is especially important because it shows how Paul’s language of “spirit, soul, and body” could be developed into a much more explicit account of the human person.

First and foremost, Irenaeus doesn’t read Paul in isolation. 

Adela Yarbro Collins emphasizes that he repeatedly incorporates Pauline texts into a larger account of salvation history in which creation, incarnation, resurrection, and final transformation form a continuous divine economy. 

His interpretation of Paul is also polemical: against Marcionite and Valentinian opponents, Irenaeus insists that the same God created the material world, acted through Israel, sent Christ, and will ultimately redeem human beings and creation rather than simply discard material existence.

This broader framework helps explain why 1 Thessalonians 5:23 matters so much to him.

Irenaeus argues that neither soul nor spirit by itself constitutes a complete human being. The soul is “part of the man,” and so is the spirit; the body likewise is only one component. The “perfect man,” in his formulation, consists in the union of the flesh, the soul, and the spirit received from God. 

This means that Irenaeus reads Paul’s “spirit, soul, and body” more literally and anthropologically than Leon Morris thinks Paul himself intended. 

For Irenaeus, however, the purpose of the distinction isn’t to produce a neutral metaphysical diagram. It’s to insist that a human being cannot be reduced either to an immortal soul or to an immaterial spirit. The flesh remains indispensable because it is part of God’s handiwork and therefore part of what God intends to save.

The most important nuance concerns what Irenaeus means by “spirit.” In his account, the spirit isn’t simply another natural substance standing alongside the soul. 

He repeatedly connects it with the Spirit of God, which is received by the soul and transforms the embodied person into one who is “spiritual and perfect.” 

This is why, in the soul vs. spirit question, Irenaeus doesn’t understand “spirit” as merely a second inner faculty parallel to the soul. 

The soul belongs to the constitution of the human being, while the spirit marks participation in God’s own life and power. A person can therefore possess body and soul and yet remain “imperfect” if the divine Spirit is absent. 

By contrast, one becomes truly “spiritual” not by escaping the flesh (Note: this is where Irenaeus rejects “Gnostic-like” interpretations of Paul), but by receiving the Spirit while remaining an embodied human being.

This is precisely how Irenaeus interprets 1 Thessalonians 5:23. Paul’s prayer that “spirit, soul, and body” be preserved until the coming of Christ becomes, for Irenaeus, evidence that all three are destined for one and the same salvation.

He asks rhetorically why Paul would pray for the preservation of these three if they were not to be reunited and restored together. 

The verse therefore supports his wider theology of resurrection: salvation includes the complete human person being brought to incorruptibility through the Spirit. 

Collins’ discussion of Irenaeus’ eschatology confirms this wider pattern: souls await bodily resurrection, and the renewed human being remains part of a restored creation rather than escaping into a purely immaterial existence. 

In Irenaeus, then, Paul’s relatively compressed language has become a much more developed anthropology. Namely, one in which body, soul, and spirit are distinguished, but only so that their ultimate unity in salvation can be affirmed.

Conclusion

While belief in the soul remains widespread today, history traced in this article shows why the familiar soul vs. spirit question has no single answer that can simply be carried unchanged from antiquity to the present. 

In early Greek thought, psychē was associated primarily with life and what departed at death; in Plato, it became increasingly central to rationality, moral identity, and hopes for immortality.

Paul inherited this vocabulary but reshaped it within a Jewish apocalyptic framework in which pneuma was closely connected with God’s transforming activity and bodily resurrection remained indispensable. 

His reference to “spirit, soul, and body” in 1 Thessalonians 5:23 therefore expresses the sanctification of the whole person more clearly than it defines three separate substances.

A century later, Irenaeus could read the same verse much more explicitly, distinguishing body, soul, and spirit while insisting that salvation ultimately embraces their unity. 

The enduring language of “soul” and “spirit,” then, reflects a long history of philosophers and Christians repeatedly rethinking what it means to be human, to relate to God, and to hope for life beyond death.