“God is not a man, that He should lie; neither the son of man, that He should repent.” – Numbers 23:19

What He hath spoken in public, He does not reverse in private. His own declaration is, “I have not spoken in secret, in a dark place of the earth: I said not unto the seed of Jacob, Seek ye Me in vain.” Whatever there may be in the sealed scroll that records God’s purposes in predestination, there cannot be anything there to contradict what is written on the open scroll of divine revelation. As to the doctrine of election, which often terrifies seeking souls, it never should do so, since there can be nothing, in the secret counsels of God, contrary to the plain promises of God recorded in His Word. He has not said “Yea” in one place, and “Nay” in another; and if He saith “Yea” to-day, He will not say “Nay” to-morrow. He himself said, long ago, “I am the Lord, I change not; therefore, ye sons of Jacob are not consumed.” Once let any message go forth out of His mouth and it shall stand fast forever.

Oh, then, what a firm foundation for faith this is! First, “God hath spoken;” and that is as good as if He had already done as He hath said; and, secondly, God hath spoken,” and that which He hath said can never be reversed. If there is a promise in the Bible made to a penitent sinner, and thou art a penitent sinner, that promise must be kept to thee. If there is a blessing promised to a believing soul, and thou art a believing soul, that blessing is sure to thee. If God hath promised to sustain thee when thou dost cast thy burden upon Him, and to bring thee through the furnace, with thy hair unsinged, He will do it, for He never yet has been false to His promise, and He never will be. Heaven and earth shall pass away, but not one jot or tittle of His Word shall ever fail. It stands, as an immutable decree, that Jehovah’s will shall be done; and this is Jehovah’s will: that, of all that He hath promised to the sons and daughters of men, not one syllable shall ever fail. Oh, how blessedly faith ought to rest on such a foundation as this! ~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/2864.cfm