"For the word of God is quick, and powerful, and sharper than any twoedged sword, piercing even to the dividing asunder of soul and spirit, and of the joints and marrow, and is a discerner of the thoughts and intents of the heart" (Hebrews 4:12).
The Word of God (both the written Word and the living Word, Jesus Christ) is "living and energizing" and is the double-edged sword of the Spirit, piercing into the deepest recesses of body, soul, and spirit, where it "discerns" even the very thoughts and intents of our hearts.
This discernment, however, is more than just understanding or insight. The Greek word for "discerner" is kritikos and is used only this one time in the Bible. Our word "critic" is derived from it, and this is an important dimension of its meaning. Its discernment is a critical, judging discernment-one which convicts and corrects, as well as one which understands.
It is paradoxical that men today presume to become critics of the Bible, when it should really be the other way around. There are textual critics who sort through the various ancient manuscripts of the Bible, trying to arrive at the original text; there are the "higher critics" who critique vocabularies and concepts, trying to show that the traditional authors did not actually write the books attributed to them; and then there are many other purely destructive critics who criticize the Bible's miracles, morals, and everything else, hoping thereby to justify their rebellion against the Word.
But the Bible still stands! It stands in judgment on our lives and our subconscious motives. It will have the final word when "the books [are] opened . . . and the dead [are] judged out of those things which were written in the books" (Revelation 20:12). It is far better to heed the constructive criticism of the Word now, than to hear its condemnation later. HMM