And if ye be Christ’s, then are ye Abraham’s seed, and heirs according to the promise. – Galatians 3:29

Permit me to draw your attention to one encouraging thought that may help to cheer the downcast and Satan-tempted child of God. Sonship is a thing which all the infirmities of our flesh, and all the sins into which we are hurried by temptation, can never violate or weaken. A man hath a child; that child on a sudden is bereaved of its senses; it becomes an idiot. What a grief that is to a father, for a child to become a lunatic or an idiot, and to exist only as an animal, apparently without a soul! But the idiot child is a child, and the lunatic child is a child still; and if we are the fathers of such children they are ours, and all the idiocy and all the lunacy that can possibly befall them can never shake the fact that they are our sons. Oh! what a mercy, when we transfer this to God’s case and ours! How foolish we are sometimes-how worse than foolish! We may say as David did, “I was as a beast before Thee.” God brings before us the truths of His kingdom; we cannot see their beauty, we cannot appreciate them; we seem to be as if we were totally demented ignorant, unstable, weary, and apt to slide. But, thanks be unto God, we are His children still! And if there be anything worse that can happen to a father than his child becoming a lunatic or an idiot, it is when he grows up to be wicked. Ungodly, vile, debauched-a blasphemer! But mark, brethren: if he be a child he cannot lose his childship, nor we our fatherhood, be he who or what he may… The prodigal was his father’s son, when he was amongst the harlots, and when he was feeding swine; and God’s children are God’s children anywhere and everywhere, and shall be even unto the end. Nothing can sever that sacred tie, or divide us from His heart. ~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/0213.cfm