12 For the word of God is living and powerful, and sharper than any two-edged sword, piercing even to the division of soul and spirit, and of joints and marrow, and is a discerner of the thoughts and intents of the heart.
and sharper [more cutting] than any two-edged sword,
The sword here is double edged. God’s Word is sharper than the sharpest sword. It can penetrate the deepest aspect of the soul. It has double power to both discern and search the soul. The power of the Word is so keen that it can do what other writings cannot. It can both perceive and distinguish between what differs in the life (Eph 6:17).
piercing [penetrating] even to the division of soul and spirit,
The word “piercing” means to go through. God’s Word can penetrate the depth of a person. It can reach into the very core of a soul. “Division” means any distinction in the person. The Bible can distinguish between what happens in the realm of the person (the “soul’) and the spiritual life (“spirit”). There is a big difference between the physical life with its human pursuits and the spiritual life of living by faith.
“Soul” and “spirit” reflect both the human and the spiritual aspects of the believer. The Bible reaches into the innermost parts of the person. The Bible can discriminate between the “soul” or the human person and what is spiritual about him. It penetrates to the point where it can distinguish between the person and his spirituality. That which is immaterial in man cannot hide from God.
and of joints and marrow,
The two terms “joints” and “marrow” speak of the interwoven physical elements of the person.
and is a discerner [critic] of the thoughts [reflections] and intents [purposes] of the heart.
The Greek word for “discerner” or critic occurs only here in the New Testament. Not only can God’s Word reach to the most accurate and intimate part of the human being, it can distinguish between a person’s thinking and his motivation. The Word of God can thoroughly and comprehensively examine the soul. The “heart” biblically is the center of one’s personal life (Mt 5:8; Prov 4:23).
God’s Word is in a category by itself.
God’s Word is able to thoroughly examine our lives (Isa 55:11). It can do what no other book can do. The penetrating power of God’s Word can probe the inmost aspects of our thinking (1 Co 4:5). The inner life of a believer is complex, and only God’s Word can sort out the intricacies of a person. Each person can become confused about his or her own motivation; they need the Word of God to examine them.
God’s Word discerns who and what we are. It can penetrate the full depth of our motivations. It is incisive into our thinking. It penetrates our self-delusion and reveals it for what it is. This is why we need to ask God to search our souls as we read the Bible (Ps 119:105). God’s Word renders us without the ability to rationalize our sins away. It reduces us to the place where we have no excuse.