Answer
Perhaps one of the best-known statements from the writer of Hebrews is that “the word of God is living and active, sharper than any two-edged sword,” and that the Word of God divides even soul and spirit (Hebrews 4:12, ESV). The “Word” here is the written Word of God—the Bible.
It is the sharpness, the keenness, of the Bible that the writer of Hebrews emphasizes: “Sharper than any double-edged sword, it penetrates even to dividing soul and spirit, joints and marrow; it judges the thoughts and attitudes of the heart” (Hebrews 4:12). The other passage where the Word is compared to a sword is Ephesians 6:17, which admonishes Christians to take up “the sword of the Spirit, which is the word of God.” Just as a physical sword can cut through a person’s body, so the spiritual sword (the Word) can penetrate to the very depths of the human heart. In fact, the Word of God is even more effectual in its cutting power than the most expertly honed double-edged blade.
What God has revealed is so precise and so accurate as to make the minutest of judgments and to be able to discern where the soul and spirit begin and end. It can even expose “our innermost thoughts and desires” (Hebrews 4:12, NLT).
Many passages of Scripture mention both “soul” and “spirit.” When this occurs in Hebrew poetry (e.g., 1 Samuel 1:15; Job 7:11; Isaiah 26:9), the parallelism would seem to equate the two terms. Other passages, such as 1 Thessalonians 5:23, however, seem to treat the soul and spirit as if they were distinct from each other. But the division is never defined or explained. Neither does the writer of Hebrews expound; he only asserts that the Word of God “pierces even to dividing soul and spirit” (Hebrews 4:12, BSB). We can’t discern that division, but God can.
So, if the Word of God can divide soul and spirit, what is the difference between the soul and the spirit? One way to look at it is that the soul is the “life force” of a person; it is the essence of humanity’s being. The spirit is related to the soul but is more specifically the immaterial part of humanity that connects with God. As commentary puts it, the Word of God reaches “even to the separation of the animal soul, the lower part of man’s incorporeal nature, the seat of animal desires, which he has in common with the brutes; compare the same Greek, 1Co 2:14, ‘the natural [animal-souled] man’ (Jude 19), from the spirit (the higher part of man, receptive of the Spirit of God, and allying him to heavenly beings)” (Jamieson, R.; Fausset, A.; and Brown, D.; A Commentary, Critical, Practical, and Explanatory on the Old and New Testaments, 1882, entry for Hebrews 4:12).
There is another way to see this passage, however. Some Bible scholars consider the soul and spirit to be one and the same thing. Instances of the phrase soul and spirit are simply a writer’s way of emphasizing the totality of the inner person. As Heinrich Meyer puts it, the reference to “soul and spirit” (and “joints and marrow”) is “a figurative expression to denote the innermost, most hidden depth of the rational life of man” (New Testament Commentary, 1880, entry for Hebrews 4:12). And John MacArthur says, “These terms [soul and spirit] do not describe two separate entities (and more than “thoughts and intentions” do) but are used as one might say “heart and soul” to express fulness. . . . Elsewhere these two terms are used interchangeably to describe man’s immaterial self, his eternal inner person” (The MacArthur Study Bible, English Standard Version, Crossway, 2010, p. 1,853).
Whether the soul and spirit actually have a dividing line, the written Word of God is living, sharp, and powerful and has the ability to judge our thoughts. Scripture has a way of laying open our innermost feelings and desires, exposing our secrets, and forcing honesty before the God who created us.
