This passage discourages many Christians, because then they believe that whatever desires lie in their heart, they should automatically reject.
Now, let us always remember to rightly divide the Word of Truth (2 Timothy 2: 15), and that man's heart needed to be changed. With the New Covenant, we have a new heart.
Of course, we see examples throughout the Old Testament from men still living under the previous administration, and what their hearts revealed:
"I said in mine heart, God shall judge the righteous and the wicked: for there is a time there for every purpose and for every work. 18I said in mine heart concerning the estate of the sons of men, that God might manifest them, and that they might see that they themselves are beasts." (Ecclesiastes 3: 17-18)
David recognized his need for a new heart:
'Create in me a clean heart, O God; and renew a right spirit within me." (Psalm 51: 10)
God promised to give His people a new heart:
"A new heart also will I give you, and a new spirit will I put within you: and I will take away the stony heart out of your flesh, and I will give you an heart of flesh." (Ezekiel 36: 26)
How does God do this? The writer of Hebrews outlines what God did through His Son Jesus:
"For this is the covenant that I will make with the house of Israel after those days, saith the Lord; I will put my laws into their mind, and write them in their hearts: and I will be to them a God, and they shall be to me a people:
11And they shall not teach every man his neighbour, and every man his brother, saying, Know the Lord: for all shall know me, from the least to the greatest.
12For I will be merciful to their unrighteousness, and their sins and their iniquities will I remember no more.
13In that he saith, A new covenant, he hath made the first old. Now that which decayeth and waxeth old is ready to vanish away." (Hebrews 8: 10-13)
"And for this cause he is the mediator of the new testament, that by means of death, for the redemption of the transgressions that were under the first testament, they which are called might receive the promise of eternal inheritance." (Hebrews 9: 15)
"And to Jesus the mediator of the new covenant, and to the blood of sprinkling, that speaketh better things than that of Abel." (Hebrews 12: 24)
We have a new heart and a news spirit today, because of Jesus!