Does not Ephesians 1:13 say:
In whom ye also trusted, after that ye heard the word of truth, the gospel of your salvation: in whom also after that ye believed, ye were sealed with that holy Spirit of promise,
That seal, afforded only to the believers, cannot be broken. Not even by the believer. Those that rebel to the extent you describe I would question their belief in the first place.
The Catch-22 of OSAS.
I have always wondered about the "once saved, always saved" doctrine, primarily because of verses like these:
"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." (Heb 6:4-6 KJV)
"Now the just shall live by faith: but if any man draw back, my soul shall have no pleasure in him. But we are not of them who draw back unto perdition; but of them that believe to the saving of the soul." (Heb 10:38-39 KJV)
"Let no man deceive you by any means: for that day shall not come, except there come a falling away first, and that man of sin be revealed, the son of perdition;" (2Th 2:3 KJV)
"Ye therefore, beloved, seeing ye know these things before, beware lest ye also, being led away with the error of the wicked, fall from your own stedfastness." (2Pet 3:17 KJV)
"He that overcometh, the same shall be clothed in white raiment; and I will not blot out his name out of the book of life, but I will confess his name before my Father, and before his angels." (Rev 3:5 KJV)
"And if any man shall take away from the words of the book of this prophecy, God shall take away his part out of the book of life, and out of the holy city, and from the things which are written in this book." (Rev 22:19 KJV)
Philip