And I will put My spirit within you… – Ezekiel 36:27

Who but the Lord could speak after this fashion? Can one man put the Spirit of God within another? Could all the church combined breathe the Spirit of God into a single sinner’s heart? To put any good thing into the deceitful heart of man is a great achievement; but to put the Spirit of God into the heart, truly this is the finger of God. Nay, here I may say, the Lord has made bare His arm, and displayed the fulness of His mighty power. To put the Spirit of God into our nature is a work peculiar to the Godhead, and to do this within the nature of a free agent, such as man, is marvellous. Who but Jehovah, the God of Israel, can speak after this royal style, and, beyond all dispute, declare, “I will put My spirit within you?” Men must always surround their resolves with conditions and uncertainties; but since omnipotence is at the back of every promise of God, He speaks like a king; yea, in a style which is only fit for the eternal God. He purposes and promises, and He as surely performs. Sure, then, is this sacred saying, “I will put My spirit within you.” Sure, because divine. O sinner, if we poor creatures had the saving of you, we should break down in the attempt; but, behold the Lord Himself comes on the scene, and the work is done! All the difficulties are removed by this one sentence, “I will put My spirit within you.” We have wrought with our spirit, we have wept over you, ‘and we have entreated you; but we have failed. Lo, there cometh One into the matter who will not fail, with whom nothing is impossible; and He begins His work by saying, “I will put My spirit within you.” The word is of grace and of God; regard it, then, as a pledge from the God of grace.

Glory be to God, who gives to sinners the indwelling of His Spirit. ~ C.H. Spurgeon

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