'Deepest' in the Bible

“Will they (the fathers) not teach you and tell you,And utter words from their hearts [the deepest part of their nature]?

Bless and affectionately praise the Lord, O my soul,And all that is [deep] within me, bless His holy name.

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.