Stone or flesh

"I will give you a new heart and put a new spirit within you; I will take the heart of stone out of your flesh and give you a heart of flesh." Ezekiel 36.26

This promise relates to the days after the ascension of the Lord Jesus Christ. But why not everybody receives the Holy Spirit? Because not everyone has been dedicating themselves  body, soul and spirit to receive it. Not all give up sin. Then, it really is hard to receive new heart and spirit.