If we fall away, not if we sin, and I already have shown you Scripture, at length.
He is talking about those who aren't saved. They dabbled in it, may have had an experience of God healing them or something for example, but they did not repent and confess. I have met people who laughed at Christianity, saying that they had tried that born again thing and it didn't work. Those are the kinds of people he is referring to.
This is the book of Hebrews written to the Jews in the First Century so your aforementioned experiences are not a good measure with which to understand it. I realize this scripture is unpleasant and uncomfortable for the OSAS teaching.
For it is impossible for those who were once enlightened, and have tasted of the heavenly gift, and were made partakers of the Holy Ghost, And have tasted the good word of God, and the powers of the world to come, If they shall fall away, to renew them again unto repentance; seeing they crucify to themselves the Son of God afresh, and put him to an open shame.
If you want a modern example, perhaps it would be someone like Frank Schaeffer. I would not say it is too late for him to repent though, as that would be presumptious. God knows how he could possibly be restored from whence he has fallen, and I hope he comes to repentance again.
I have only presented the Protestant KJV to you; there is no call to attack Catholics. Yes, God wants to save people, which it why he tells us over and over and over again in the Old and New Testament books to obey him. But if the wicked will turn from all his sins that he hath committed, and keep all my statutes, and do that which is lawful and right, he shall surely live, he shall not die. All his transgressions that he hath committed, they shall not be mentioned unto him: in his righteousness that he hath done he shall live. Have I any pleasure at all that the wicked should die? saith the Lord GOD: and not that he should return from his ways, and live? But when the righteous turneth away from his righteousness, and committeth iniquity, and doeth according to all the abominations that the wicked man doeth, shall he live? All his righteousness that he hath done shall not be mentioned: in his trespass that he hath trespassed, and in his sin that he hath sinned, in them shall he die. Yet ye say, The way of the Lord is not equal. Hear now, O house of Israel; Is not my way equal? are not your ways unequal? When a righteous man turneth away from his righteousness, and committeth iniquity, and dieth in them; for his iniquity that he hath done shall he die. Again, when the wicked man turneth away from his wickedness that he hath committed, and doeth that which is lawful and right, he shall save his soul alive. Because he considereth, and turneth away from all his transgressions that he hath committed, he shall surely live, he shall not die. Yet saith the house of Israel, The way of the Lord is not equal. O house of Israel, are not my ways equal? are not your ways unequal? Therefore I will judge you, O house of Israel, every one according to his ways, saith the Lord GOD. Repent, and turn yourselves from all your transgressions; so iniquity shall not be your ruin. Cast away from you all your transgressions, whereby ye have transgressed; and make you a new heart and a new spirit: for why will ye die, O house of Israel? For I have no pleasure in the death of him that dieth, saith the Lord GOD: wherefore turn yourselves, and live ye.
That’s not uncomfortable or unpleasant at all. As I showed in my previous posts to you. There is nothing in that passage that says those people were saved and had the indwelling of the Holy Spirit. They rejected the Holy Spirit and the gospel thus rejected the death and resurrection of Christ.