The word “Heart” is crucial to understanding many topics, including the new covenant, but is least understood and most misused. Consider the following verses and examine the usage of “heart”.
For wisdom is a loving spirit; and will not acquit a blasphemer of his words: for God is witness of his reins, and a true beholder of his heart, and a hearer of his tongue.
Immediately, it is obvious that the heart does not refer to the physical, beating heart, as it is used in conjunction with the words reins and tongue. Tongue refers to the words you speak, and reins often refer to your mind, innermost emotions, deepest motives, etc. This relationship ensures that the author intends for heart to mean something else.
And GOD saw that the wickedness of man was great in the earth, and that every imagination of the thoughts of his heart was only evil continually.
Every imagination of man’s heart was wicked! An imaginative heart links the heart more to something aware and conscious. The next verse further solidifies and clarifies the meaning.
And he bowed the heart of all the men of Judah, even as the heart of one man; so that they sent this word unto the king, Return thou, and all thy servants.
The hearts of all the men of Judah were as one. They were united in their want for the king to return. Heart maps most accurately to the word “desire” in all these verses, even in these additional ones: Ecclesiastes 8:9, Luke 6:45, Ecclesiasticus 26:4, and throughout the Scriptures without a doubt.
Your heart is your desire.
This understanding and acceptance is paramount when evaluating scriptures such as the New Covenant (Jeremiah 31:31-33, Hebrews 8:8-10) to establish the meaning.