christiang, earlier you wrote, "You're not getting it, do you not understand that someone who is baptized with the holy spirit can NEVER sin again?"
Now you are saying, "even if it were possible for someone who has the holy spirit to fall away". You sound confused.
The author of the Hebrews certainly appeared to think it was possible for one to fall away after receiving the power of the holy spirit. Christ even foretold a falling away:
"Then they will deliver you up to tribulation and put you to death, and you will be hated by all nations for my name's sake. And then many will fall away and betray one another and hate one another." -- Mat 24:9-10 ESV
Christ's epistles to the seven churches in Asia are loaded with warnings against falling away. For example:
"But I have this against you (Ephesus), that you have abandoned the love you had at first. Remember therefore from where you have fallen; repent, and do the works you did at first. If not, I will come to you and remove your lampstand from its place, unless you repent." -- Rev 2:4-5 ESV
Peter gave this warning:
"You therefore, beloved, knowing this beforehand, take care that you are not carried away with the error of lawless people and lose your own stability." -- 2Pet 3:17 ESV
Why all the warnings? It seems the Judaizers (those promoting the law of Moses) were making many Christians fall away. For example:
"You are severed from Christ, you who would be justified by the law; you have fallen away from grace." -- Gal 5:4 ESV
"I know thy works, and tribulation, and poverty, (but thou art rich) and I know the blasphemy of them which say they are Jews, and are not, but are the synagogue of Satan. Fear none of those things which thou shalt suffer: behold, the devil shall cast some of you into prison, that ye may be tried; and ye shall have tribulation ten days: be thou faithful unto death, and I will give thee a crown of life." -- Rev 2:9-10 KJV
All in Asia abandoned Paul (e.g., his teachings), at least at time he wrote this letter:
"Guard, through the Holy Spirit who dwells in us, the treasure which has been entrusted to you. You are aware of the fact that all who are in Asia turned away from me, among whom are Phygelus and Hermogenes." -- 2Tim 1:14-15 NASB
That falling away by those in Asia may have been the reason for Christ's urgent warnings to the seven Churches in the Revelation.
In any case, you appear to have fallen into the same literary trap that the rulers of first-century Jerusalem fell into, which ultimately led to their destruction:
"But the word of the Lord was unto them precept upon precept, precept upon precept; line upon line, line upon line; here a little, and there a little; that they might go, and fall backward, and be broken, and snared, and taken. Wherefore hear the word of the Lord, ye scornful men, that rule this people which is in Jerusalem. Because ye have said, We have made a covenant with death, and with hell are we at agreement; when the overflowing scourge shall pass through, it shall not come unto us: for we have made lies our refuge, and under falsehood have we hid ourselves: Therefore thus saith the Lord God, Behold, I lay in Zion for a foundation a stone, a tried stone, a precious corner stone, a sure foundation [the anointing and ministry of Christ]: he that believeth shall not make haste. Judgment also will I lay to the line, and righteousness to the plummet: and the hail shall sweep away the refuge of lies, and the waters shall overflow the hiding place. And your covenant with death shall be disannulled, and your agreement with hell shall not stand; when the overflowing scourge shall pass through, then ye shall be trodden down by it." -- Isa 28:13-18 KJV
All of that was fulfilled in the first century.
Perhaps everything will make more sense to you if you start relying on every Word of God, rather than a verse here and a verse there (that is, "here a little, and there a little").
Rev