6 This parable spake Jesus unto them: but they understood not what things they were which he spake unto them.
7 Then said Jesus unto them again, Verily, verily, I say unto you, I (The Word) am the door of the sheep.
8 All that ever came before me are thieves and robbers: but the sheep did not hear them.
9 I (The Word) am the door: by me if any man enter in, he shall be saved, and shall go in and out, and find pasture.
10 The thief cometh not, but for to steal, and to kill, and to destroy: I am come that they might have life, and that they might have it more abundantly.
11 I am the good shepherd: the good shepherd giveth his life for the sheep. 12 But he that is an hireling, and not the shepherd, whose own the sheep are not, seeth the wolf coming, and leaveth the sheep, and fleeth: and the wolf catcheth them, and scattereth the sheep. 13 The hireling fleeth, because he is an hireling, and careth not for the sheep.
14 I am the good shepherd, and know my sheep, and am known of mine. 15 As the Father knoweth me, even so know I the Father: and I lay down my life for the sheep.
16 And other sheep I have, which are not of this fold: them also I must bring, and they shall hear my voice; and there shall be one fold, and one shepherd.
17 Therefore doth my Father love me, because I lay down my life, that I might take it again. 18 No man taketh it from me, but I lay it down of myself. I have power to lay it down, and I have power to take it again. This commandment have I received of my Father.
19There was a division therefore again among the Jews for these sayings. 20And many of them said, He hath a devil, and is mad; why hear ye him? 21Others said, These are not the words of him that hath a devil. Can a devil open the eyes of the blind?
22And it was at Jerusalem the feast of the dedication, and it was winter. 23 And Jesus walked in the temple in Solomon’s porch. 24 Then came the Jews round about him, and said unto him, How long dost thou make us to doubt? If thou be the Christ, tell us plainly.
25 Jesus answered them, I told you, and ye believed not: the works that I do in my Father’s name, they bear witness of me. 26 But ye believe not, because ye are not of my sheep, as I said unto you.
27 My sheep hear my voice, and I know them, and they follow me: 28 And I give unto them eternal life; and they shall never perish, neither shall any pluck them out of my hand. 29 My Father, which gave them me, is greater than all; and no man is able to pluck them out of my Father’s hand. 30 I and my Father are one.
(Certainly if we hear the voice of Jesus and follow HIM, we will never perish. This is the key to this scripture. We can be cut off if we fail to follow HIM after hearing HIS voice. Paul tells us we must run the race to win. Paul said in I Cor. 9 that HE kept "under his body" lest when he preached to others he be a castaway. So Paul understood he could be cut off.
Also we are told the following ... Romans 11 ... 21 For if God spared not the natural branches, take heed lest he also spare not thee. 22 Behold therefore the goodness and severity of God:on them which fell, severity; but toward thee, goodness, if thou continue in his goodness:otherwise thou also shalt be cut off. 23 And they also, if they abide not still in unbelief, shall be grafted in:for God is able to graff them in again.
And there are those persons God turns over to a strong delusion that they may be damned because they knew the truth but took pleasure in unrighteousness.
II Thess. 2 ...
10 And with all deceivableness of unrighteousness in them that perish; because they received not the love of the truth, that they might be saved. 11 And for this cause God shall send them strong delusion, that they should believe a lie:12 That they all might be damned who believed not the truth, but had pleasure in unrighteousness.
The key is to hear HIM and to follow HIM, doing as HE instructs as long as we are on this earth and if that is the case we will never perish. No man will be able to pluck us out of HIS hand if we continue to do that which Jesus says by HIS Spirit. No event will pluck us out of HIS hand if we continue in HIS Word to us, doing what HE says. We overcome all through that given us by the Spirit of God and by holding fast to that word HE gives us.
And if we do overcome, we have the following promise:
Rev. 3 ... 5 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.
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John 10
31 Then the Jews took up stones again to stone him.
32 Jesus answered them, Many good works have I shewed you from my Father; for which of those works do ye stone me?
33 The Jews answered him, saying, For a good work we stone thee not; but for blasphemy; and because that thou, being a man, makest thyself God.
34 Jesus answered them, Is it not written in your law, I said, Ye are gods? 35 If he called them gods, unto whom the word of God came, and the scripture cannot be broken; 36 Say ye of him, whom the Father hath sanctified, and sent into the world, Thou blasphemest; because I said, I am the Son of God?
37 If I do not the works of my Father, believe me not. 38 But if I do, though ye believe not me, believe the works: that ye may know, and believe, that the Father is in me, and I in him.
39 Therefore they sought again to take him: but he escaped out of their hand, 40 And went away again beyond Jordan into the place where John at first baptized; and there he abode. 41 And many resorted unto him, and said, John did no miracle: but all things that John spake of this man were true. 42 And many believed on him there.