Doug,

You had referred to Hebrews 6:

Hebrews 6:4 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,

  5 And have tasted the good word of God, and the powers of the world to come,

  6 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.

Is it possible that Jesus will keep believers from the kind of falling from which they cannot repent?

Jude 24 Now unto him that is able to keep you from falling, and to present you faultless before the presence of his glory with exceeding joy,

Since from that kind of falling they cannot repent, otherwise then why would Jesus also say to repent from falling?

Revelation 2:5 Remember therefore from whence thou art fallen, and repent, and do the first works; or else I will come unto thee quickly, and will remove thy candlestick out of his place, except thou repent.

Doesn't the LORD mention believers falling?

Psalms 37:24 Though he fall, he shall not be utterly cast down: for the LORD upholdeth him with his hand.

Psalms 145:14 The LORD upholdeth all that fall, and raiseth up all those that be bowed down.

Proverbs 24:16 For a just man falleth seven times, and riseth up again: but the wicked shall fall into mischief.

Daniel 11:35 And some of them of understanding shall fall, to try them, and to purge, and to make them white, even to the time of the end: because it is yet for a time appointed.

Micah 7:8 Rejoice not against me, O mine enemy: when I fall, I shall arise; when I sit in darkness, the LORD shall be a light unto me.

James 1:2 My brethren, count it all joy when ye fall into divers temptations;

Wasn't the church of the Galatians bewitched by the heresy, no longer believing in saving grace,

but had gone back to justification by the law, instead?

Galatians 3:1 O foolish Galatians, who hath bewitched you, that ye should not obey the truth, before whose eyes Jesus Christ hath been evidently set forth, crucified among you?

Galatians 5:4 Christ is become of no effect unto you, whosoever of you are justified by the law; ye are fallen from grace.

Was the church of the Galatians thus damned, impossible to repent from?

If so, then why did Paul bother to write the letter to them?

Hebrews 6 mentions that it would be impossible for someone to repent from falling away like that.

So, if someone is truly a believer, would then be impossible for that person to undo the blood of Jesus?

If there is no sin great enough that the blood of Jesus can forgive?

then which sin is great enough for a believer to commit, that would be more powerful than the blood of Jesus,

that could undo the power of the blood, the power of the adoption, and the power of the indwelling Holy Ghost?

Was not Paul writing to the Hebrews, of which many were not believers,

and that possibly Hebrews 6:4-6 rather like a rhetorical question to the unbelieving Hebrews,

that were refusing to give up justification by the law, for trusting in Jesus?

After all, the transition of the book of Acts was nearly finished, and the temple soon to be destroyed by the Romans?

Wasn't the book of Hebrews then, like a last chance to Israel to believe the gospel, before 70 AD would come upon them?

So, wouldn't that impossibility be for those Hebrews who had heard the gospel,

and seen the signs and wonders, and heard the people speaking in tongues,

and still refused to believe the gospel and to be saved by grace through faith in Jesus,

by instead going back to the law for justification, with a temple about to be destroyed?