…begin not to say within yourselves, We have Abraham as our father… – Like 3:8

As soon as ever John began to preach, the men of Jewish race, proud of their pedigree, pressed near; and John, with all the courage that a servant of the Lord could have, said, “Begin not to say within yourselves, We have Abraham to our father: for I say unto you, That God is able of these stones to raise up children unto Abraham.” You see the drift of his preaching, do you not? He says, practically, “Men and women, there is no virtue in your boasted privileges, there is no merit in your religious descent. As for supposing yourselves to be the peculiar people of God, you are not to be saved that way. Say not, We have Abraham as our father.” Oh, how many hug that idea, “My father was a Christian.” Others say, “Well, I live in a Christian country.” They suppose that there is something in the very race from which they have sprung. Away with all such notions, for whatever external privileges you may have had, they are not sufficient to secure salvation for you.

So John spoke right straight out; and this, I believe, is a great way of preparing men for coming to Christ, when you tell them, “It is not your early training, it is not your going to church or chapel, it is not your infant sprinkling and your confirmation, it is not even your adult baptism, nor your saying prayers and reading the Bible, that will save you; but ‘ye must be born again.’ There must be an inward spiritual change, wrought by the Holy Spirit. You must believe in Jesus Christ, whom God has sent, and you must so believe in Him as to be made new creatures in Him, or else you cannot be saved.” Now, when men realize that all this is true, it startles them out of their false refuges, and makes them ready to flee to the only true refuge… ~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/2404.cfm

“To make ready a people prepared for the Lord.”- Luke 1:17

John was the herald of Christ; he was to prepare the way for the coming King, but from this text it appears that he was to do more than that. He was not only to make the road ready for the Lord, but he was also “to make ready a people prepared for the Lord.” That was a great work, a task in which he would require strength and wisdom greater than his own. He would need that the Spirit of God, who was to be given without measure to the coming One, should also be in a measure within himself, if he should really “make ready a people prepared for the Lord.” This is not at all a usual expression; at first sight, it hardly looks to us like a gospel expression. We sang just now-

“Just as I am-and waiting not
To rid my soul of one dark blot,
To Thee, whose blood can cleanse each spot,
O Lamb of God, I come.”

We sang over and over again those words, “Just as I am,” “Just as I am,” and we are prone to protest against the idea of being prepared for Christ; we preach constantly that no preparation is needed, but that men are to come to Jesus just as they are. Yet here is John the Baptist set apart “to make ready a people prepared for the Lord.” The fact is, dear friends, that to get men to come to Jesus just as they are, is not an easy thing. To get them to give up the idea of preparing, to get them prepared to come without preparing, to get them ready to come just as they are, this is the hardest part of our work, this is our greatest difficulty… Only the grace of God, working mightily through the Word, by the Spirit, will prepare men to come to Christ thus, prepared by being unprepared so far as any fitness of their own is concerned. The only fit state in which they can come is that of sinking themselves, abandoning all idea of helping Christ, and coming in all their natural impotence and guilt, and taking Christ to be their all in all. ~ C. H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/2404.cfm

Therefore if any man be in Christ, he is a new creature: old things are passed away; behold, all things are become new. 2 Corinthians 5:17

What is meant by the Christian being a new creature? Three thoughts seem to me to spring up from the words, and the first is, the believer must then have been the subject of a radical change. He is said to be a new creature, which is of all things a most sweeping change. There are many changes which a man may undergo, but they may be far from being radical enough to be worth calling a new creation. Saul is among the prophets: hear how he prophesies; if they speak with sacred rapture the secrets of God, so doth he. Is not Saul converted-the Scripture tells us that God gave him another heart! Ay, another heart, but not a new heart. A man may be changed from one sin to another, from reckless profanity to mocking formality, from daring sin to hypocritical pretension to virtue; but such a change as is very far from being saving, and not at all like the work which is called a new creation. Ahab went and humbled himself after his murder of Naboth, and God turned away His vengeance for awhile from him, but that temporary humiliation of Ahab was no sign of a renewal of his nature; it was like the changes of the sea, which today is smooth, but which anon will be as ravenous after wrecks as ever, being still unchanged in its nature, still voracious and cruel, fickle and unstable. Ahab may humble himself, but he is Ahab still, and as Ahab will he go down into the pit.

No doubt there are great moral changes wrought in many which are not saving. I have seen a drunkard become sober; I have known persons of debauched habits become regular; and yet their changes have not amounted to regeneration or the new birth. ..unless the change shall go far deeper than the outward life, he is not saved-he is not a new creature, and, therefore, he is not in Christ Jesus…Do you see, then, how very searching the word is here, a “a new creature,” absolutely a new creation. It is a root and branch change; not an alteration of the walls only, but of the foundation; not a new figuring of the visible tapestry, but a renewal of the fabric itself. Regeneration is a change of the entire nature from top to bottom in all senses and respects. Such is the new birth, such is it to be in Christ and to be renewed by the Holy Ghost.  ~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/0881.cfm