Hebrews 4:12,13

Hebrews 4:12-13 give a fresh reason for this warning.

For the word of God is quick (i.e living) and powerful. But what is ‘the word of God'? The common Patristic interpretation refers it to the Word incarnate, the personal ‘Word' of the writings of St. John: so also Owen and many others. But that use of the term is peculiar in the New Testament to St. John, unless this be an instance. And the interpretation seems hardly appropriate to the description that is here given of it; nor is Christ ever so named in the Epistle itself, where ‘the Son of God' is His common title. Had the author been familiar with ‘the Word' in that personal sense, he would certainly have used it (as he did not) in Hebrews 11:3. The ordinary meaning, therefore, is to be preferred the word of which he has been speaking the word especially which excludes the unbeliever from the promised rest, and denounces against him the Divine indignation. The description is true of all Scripture, but emphatically true of the passages which condemn disobedience. This word is a living word not, as we sometimes say of a law, ‘a dead letter,' having its place in our statute book, but never executed having living power, and so something of the attributes of Him who is ‘the living God;' and powerful, energic, operative, not inefficient, as if God never meant to execute it, or as if He had no means of carrying it into execution. The sentence that the unbeliever shall not enter into God's rest is the utterance of a living force, not a dead law, which is mighty enough to execute the Divine purpose in relation to transgression, and is sure to execute it. Nor only so: and sharper far (a double comparative) than any two-edged sword (literally two-mouthed), i.e a sword sharpened on both edge and back, cutting both ways, and peculiarly trenchant (Isaiah 49:2; Revelation 1:16, etc.; see also Ephesians 6:17).

Piercing through, even to the dividing of soul and spirit, of both joints and marrow. This quality of the Word has been regarded by some as a mere description of the power of the Word of God to produce conviction, to show the sinner the falsehood and the wickedness of even his inmost thoughts; but this explanation anticipates what follows, and is hardly consistent with the context. It is better to regard the words as a completion of the previous thought. The soul was regarded by the Greeks as the principle of animal life and action; the spirit, as the principle of rational life and action. To separate them is to destroy the life of the man, the description being taken from the inner nature. Similarly the joints or limbs, of which the bones are the framework, and marrow are also closely connected; to separate them is to produce great pain and death itself, the description being taken from the physical life. The threatening of God against disbelief is a threatening that will certainly be executed, and when executed intensest suffering, destruction, and misery will ensue. Suffering with the possibility of destruction not necessarily destruction may be the idea, as in similar passages (Luke 2:35; Jeremiah 4:10, LXX.); but this interpretation does no justice to the strong word the dividing asunder of soul and spirit. On either interpretation the lesson is solemn and instructive. What occurred in the case of the Israelites who fell by hundreds of thousands in the wilderness will occur under the Gospel with aggravated suffering if men will not believe.... Nor does this word take cognizance of outward acts only, open apostasy, it is a discerner and judge of the thoughts and intents (or rather of the inclinations and thoughts) of the heart. Feelings and thoughts, desires and ideas (opinions as we call them), are equally under its jurisdiction; backslidings of heart, as well as of life, it marks and condemns. The religion of Christ is eminently spiritual. Not the outer life only; the inmost nature, mental and emotional, must be subject to the Divine authority, and conformed to the Divine will.