“For the word of God is living and active, sharper than any two-edged sword, piercing to the division of soul and of spirit, of joints and of marrow, and discerning the thoughts and intentions of the heart. And no creature is hidden from his sight, but all are naked and exposed to the eyes of him to whom we must give account.” (Heb. 4:12-13)
“…his sight…” …the eyes of him…” Jews in the time in which Hebrews was written understood “the word of god” (Devar HaElohim) to be a name for Jesus[RM1] . They also had the understanding that the word of God encompassed all of God’s revelation and instruction, which would include the Holy Scriptures. So we have in this passage the “word of God” being Christ Himself, and the “word of God” as His written revelation.
In any case and in either case, Hebrews 4:12-13 is about Jesus. See also:
http://www.biblestudytools.com/commentaries/gills-exposition-of-the-bible/hebrews-4-12.html
We might paraphrase the passage as follows: Jesus Christ is alive and active, resurrected and at the Father’s right hand. Christ, both directly and through His written revelation, is able to divide and separate the natural man from the spiritual man, the fallen man from the pardoned and justified man; He sees deeply, down into the inner thoughts, motivations and intentions of a person. No one hides from Him, for He is omniscient, and the plain truth about a person is laid open and obvious before Him. Everyone will therefore give a complete account to Him when all is said and done (See Revelation.)
Many – including many professing Christians – would find their blood pressure going up right about now. “How can I ever survive giving a complete account of my life to Jesus? There are so many sins, every day, and He will see all of that and I will be evaporated or sent straight to hell…”
This is an appropriate response for an unbeliever, or for a “nominal” Christian (a Christian in name and outward church-ianity only), but not for a person whose faith and trust are in Christ and the Gospel. For them, the Gospel of Christ offers complete rest from all such insecurity. There is ultimate rest available from the sins of the past, present and future, and from mortal fear of condemnation and judgment.
Those whose names are written in the Lamb’s Book of Life are justified in Christ - their sins are remembered no more. They have entered into God’s rest by grace through faith in Christ.
As Jesus spoke at Matthew 11:28-29, “Come to me, all who labor and are heavy laden, and I will give you rest. Take my yoke upon you, and learn from me, for I am gentle and lowly in heart, and you will find rest for your souls.”
We know that Jewish Christians in the AD 60’s were surrounded by Greco-Roman (pagan, Hellenistic) culture. Moreover, these Jewish Christians were still in very close quarters and proximity with unbelieving Jews. Separation of Jewish believers and unbelievers had not yet taken its course. Therefore, the pressure on believing Jews to revert back to Judaism and give up their identification with Christ was severe. The passage above (Heb. 4:12-13) is part of several chapters extolling the supremacy and preeminence of Christ and calling Jewish converts and seekers to persist and persevere in their Christian faith and to resist the pressure to run back into the arms of the culture around them.
Like our early Jewish brothers and sisters, we are subject to tremendous social and cultural pressure to play church, “act” like believers, and not hold fully to the faith of the apostles and the Gospel of Christ. Having one foot in the faith and the other foot in the world which hates and despises the faith, is anything but “restful.” It is, in fact, full of contradiction, frustration, uncertainty, insecurity, condemnation, and the ever-present danger of apostasy, backsliding, and failure to come to a full, trusting, saving, restful faith in Christ and the Gospel.
We are called by the writer of Hebrews to fully enter the “Sabbath rest” spoken of in Hebrews chapter 4. He calls on us to enter eternal rest from our work (v.10), which cannot save us by any means, and from strife and condemnation; such a rest comes only by grace through faith that endures. We must give each other continuous, repetitive encouragement, teaching and reminding one another of the Gospel and the key doctrines of the faith.
Therefore, In order to remain in the faith and thereby in God’s rest, we need to be continuously steeped and trained in the scriptures. The Scriptures contain God’s revelation of Truth and all we need for life and growth in Him. Our sanctification depends upon our continuous growth in the Scriptures.
How do we know sanctification comes through the word of God, that is, through Jesus Christ and the Scriptures? We can take that up with Jesus, who prayed to the Father: “Sanctify them in the truth; your word is truth.” (John 17:17)