A new heart also will I give you, and a new spirit will I put within you… – Ezekiel 36:26

God in our nature is a very wonderful conception! God in the babe at Bethlehem, God in the carpenter of Nazareth, God in the “Man of sorrows,” God in the Crucified, God in Him who was buried in the tomb-this is all marvellous. The incarnation is an infinite mystery of love; but we believe it. Yet, if it were possible to compare one illimitable wonder with another, I should say that God’s dwelling in His people and that repeated ten thousand times over, is more marvellous. That the Holy Ghost should dwell in millions of redeemed men and women, is a miracle not surpassed by that of our Lord’s espousal of human nature. For our Lord’s body was perfectly pure, and the Godhead, while it dwells with His holy manhood, does at least dwell with a perfect and sinless nature; but the Holy Spirit bows Himself to dwell in sinful men; to dwell in men who, after their conversion, still find the flesh warring against the spirit, and the spirit against the flesh; men who are not perfect, though they strive to be so; men who have to lament their shortcomings, and even to confess with shame a measure of unbelief.

Believers in the Lord Jesus Christ, you have the Spirit of God, for “if any man have not the Spirit of Christ, he is none of His.” You could not bear the suspicion that you are not His; and therefore, as surely as you are Christ’s, you have His Spirit abiding in you. The Saviour has gone away on purpose that the Comforter might be given to dwell in you, and He does dwell in you. Is it not so? If it be so, admire this condescending God, and worship and praise His name. ~ C.H. Spurgeon

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