Wherefore I say unto you, All manner of sin and blasphemy shall be forgiven unto men: but the blasphemy against the Holy Ghost shall not be forgiven unto men. -Matthew 12:31

Remember, there is a limit to God’s mercy…If I read the Bible rightly, there is one sin which can never be forgiven. It is the sin against the Holy Ghost. Tremble, unpardoned sinners, lest ye should commit that. If I may tell you what I think the sin against the Holy Ghost is, I must say that I believe it to be different in different people; but in many persons, the sin against the Holy Ghost consists in stifling their convictions…Perhaps the very next time thou laughest over a sermon, or mockest at a prayer, or despisest a text, the very next oath thou swearest, God may say, “He is given to idols, let him alone; My Spirit shall no more strive with that man; I will never speak to him again.”

Ah! poor sinner, if thou knewest that Christ died for thee, and I know that He did, if thou repentest, if thou knewest that one day thou wilt be His, wouldst thou spit upon Him now? Wouldst thou scoff at God’s day, if thou knewest that one day it will be thy day? wouldst thou despise Christ, if thou knewest that He loves thee now, and will display that love by-and-bye? Oh! there are some of you that will loathe yourselves when you know Christ because you did not treat Him better. He will come to you one of these bright mornings, and He will say, “Poor sinner, I forgive you;” and you will look up in His face, and say. “What! Lord, forgive me? I used to curse Thee, I laughed at Thy people, I despised everything that had to do with religion. Forgive me?” “Yes,” says Christ, “give Me thy hand; I loved thee when thou hatedst Me, come here!” ~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/0084.cfm