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

To me there is much charm in the thought that this text is an individual and personal word. The Lord means, “I will put My spirit within you”: that is to say, within you, as individuals. “I will put My spirit within you” one by one. This must be so since the connection requires it. Now, a new heart can only be given to one person. Each man needs a heart of his own, and each man must have a new heart for himself… “And I will take away the stony heart out of your flesh, and I will give you an heart of flesh” -these are all personal, individual operations of grace. God deals with men one by one in the solemn matters of eternity, sin, and salvation. We are born one by one, and we die one by one: even so we must be born again one by one, and each one for himself must receive the Spirit of God. Without this a man has nothing. He cannot be caused to walk in God’s statutes except by the infusion of grace into him as an individual.

My dear hearers, you who have long been seeking salvation, but have not known the power of the Spirit-this is what you need. You have been striving in the energy of the flesh, but you have not understood where your true strength lieth. God saith to you, “Not by might, nor by power, but by My Spirit, saith the Lord”; and again, “I will put My spirit within you.” …Lift up your heart in prayer to God, and ask Him to pour upon you the Spirit of grace and of supplications. Plead with the Lord, saying, “Let Thy good Spirit lead me. Even me.” Cry, “Pass me not, my gracious Father; but in me fulfil this wondrous word of thine, ‘I will put My spirit within you.'” ~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/2200.cfm