Timothy,
Luke 8:13 Parable: Four groups, first 3 don't believe, last one believes and is saved. That 2nd group you cited received the word but did not respond to it. Faith that does not produce works is not faith at all.
Matthew 24:13 and Mark 13:13 are talking about the tribulation period. It is saying that during this time if you can manage to survive there is hope of being rescued at the end of the tribuylation. Saved doesn't always mean salvation of the soul.
Mark 5:13, (I assume you mean Matt 5:13) The question is not, If a man lose his grace, how shall that grace be restored to him? but, Since living Christianity is the only "salt of the earth," if men lose that, what else can supply its place? What follows is the appalling answer to this question.
John 15:6 The saved abide in him, the unsaved don't. This verse doesn't even hint that this man EVER abode in Christ.
Romans 11:22 Please read the entire chapter, it is talking about the nation of Israel and the Gentiles, not individual Christians.. It is talking about how that grafting the Jews back in will be an easier task than grafting in the Gentiles because they are "naturally" a part of the original plant.
1 Corinthians 9:27 Castaway = unapproved. He lost the race. The race isn't to the salvation finish line, it is to the successful Christian life finish line. Paul is telling the Corinthians that if even he has to worry about controlling himself how much more should they..
1 Corinthians 10:1-12 Reading verse 12 as saying , "let him that is saved take heed lest he lose that salvation.", is missing the point. God is saying that the Jew were our examples to keep us from evil and to be well pleasing to him. They committed evil and died, if we commit evil and become unpleasing to God we may die also. They didn't stop being Jews, they died. We will not stop being Christians we may die.
Galations 6:7 Thank you for making my point. If I sow to the Spirit and don't reap life everlasting then God is mocked. It is true in the big things (salvation) and it is true in the small things (well doing).
1 Timothy 4:1 Some people within the church will be apostate, some shall depart from "the faith", doctrine, truth. In context it is talking about teachings, not grace.
2 Timothy 2:11,12 If the "we" in vs 11-13 are Christians then the "them" and "they" in v14 must not be, but that wouldn't be right. These are logic questions posed to Timothy. If…then, is used the way we use it a lot on this board. I find it interesting that in this section of the Bible that includes the admonition to rightly divide the word of truth we have some who say that when I end up in heaven I will be able to say that I did "something" to assure my place there.
Hebrews 6:4 This does indeed prove that you can't get saved then lost and then saved again. It doesn't however, prove you can get lost. The author (God) is making the point that salvation is a one time deal, and that IF it were possible (not that it is) that would be the end of it.
Hebrews 6:12 Look at the phrases in this section, "full assurance", "through faith and patience inherit", "Surely blessing I will bless thee", "strong consolation", "anchor of the soul"," both sure and stedfast".God made us a promise and it is IMPOSSIBLE for our hope to be unsure.
Hebrews 10:26-29 This is one I wish I had thought of first. Nothing does more despite to the Spirit of Grace than the idea that works can keep it. Nothing trods the Son of God under foot more than to say his sacrifice wasn't enough by itself. Nothing counts the blood more unholy (not able to separate us to God) than insecurity.
Hebrews 10:39 This is true. We ARE NOT of them that draw back unto perdition. Christians don't do that.
1 John 5:16 Nothing to do with salvation.
Revelation 3:5 Best answer is I John 5:4-5 For whatsoever is born of God overcometh the world: and this is the victory that overcometh the world, even our faith. 5Who is he that overcometh the world, but he that believeth that Jesus is the Son of God?