Hebrews 4:11-12

Let us therefore make every effort to enter that rest [of God, to know and experience it for ourselves], so that no one will fall by following the same example of disobedience [as those who died in the wilderness]. For the word of God is living and active and full of power [making it operative, energizing, and effective]. It is sharper than any two-edged sword, penetrating as far as the division of the soul and spirit [the completeness of a person], and of both joints and marrow [the deepest parts of our nature], exposing and judging the very thoughts and intentions of the heart.