Uhhhh, that’s NOT what the Bible says.
Well, yes it is. We disagree.
2 Peter 2:20-22 For if they, having escaped the defilements of the world through the KNOWLEDGE of our Lord and savior Jesus Christ, again become entangled and overcome by them, their last condition is worse than their first.
For it would have been better for them not to have KNOWN the way of righteousness than after knowing it to turn back from the holy commandment handed down to them.
Here, Peter illustrates that those who had a full, experiential knowledge (epignosei) of Christ – CHRISTIANS – who can fall back into darkness and LOSE their salvation by their own doing.
Who is the "they" Peter is speaking of here, BOL? The "they" refers directly to "false teachers... who... secretly bring in destructive heresies, even denying the Master who brought them, bringing upon themselves swift destruction" and the "many" who "will follow" them. You might read back through that very chapter ~ just the previous paragraph or two should be more than enough. It is quite possible to all about Jesus, but still not know ~ virtually synonymous with love ~ Him, and Him not know that person. Indeed, at the Judgment, to many ~ despite what they had been convinced of ~ He will say to many,
"Depart from me, for I never knew you."
Matt. 5:13 You are the salt of the earth. But if salt loses its taste, with what can it be seasoned? It is no longer good for anything but to be thrown out and trampled underfoot.
This one is self-explanatory . . .
God can use ~ season ~ anyone, even those who hate Him and/or are not called according to His purposes, for a time. And we have to bear in mind Jesus's purpose in His Olivet discourse... His overarching purpose was to proclaim the general call of the Gospel, that everyone is eligible. There is an inward call that is issued only to God's elect, which is what Paul is talking about in Romans 8 (see below), but what Jesus is talking about is the general, outward call to everyone.
2 Peter 3:17
Therefore, dear friends, since you already know this, be on your guard so that you may not be carried away by the error of lawless men and fall from your secure position.
Peter is warning the faithful not to fall back into sin and lawlessness.
Sure he is, I agree... because they, presumably, have received this inward call, issued, as I said, by God via His Spirit. We can stumble/fall from time to time, and inevitably do, sinners that we are, but a good thing to remember here, I think, is what Jude says in his short letter, that God is able to keep us from stumbling:
"...to Him Who is able to keep you from stumbling and to present you blameless before the presence of His glory with great joy, to the only God, our Savior, through Jesus Christ our Lord, be glory, majesty, dominion, and authority, before all time and now and forever. Amen." (Jude 24-25).
God gives us the TOOLS – but WE must cooperate with His grace.
I'm not quite sure what you mean by "cooperating with His grace." I have an idea, but... :) But Paul speaks directly to this in all his letters/epistles, and maybe most clearly in Philippians 2:12-13, which I cite below. But to use the same language you are using here, God's promise ~ and all God's promises have their 'yes' and 'amen' in Christ Jesus ~ is that
even if, from time to time, we don't "cooperate with His grace," even so,
"if (as John says)
we confess our sins, he is faithful and just to forgive us our sins and to cleanse us from all unrighteousness" (1 John 1:9). And Paul also says that God, by the power and working of His Holy Spirit, is the one who sustains us to the end. What Paul writes to the Roman Christians (specifically in Romans 8) is magnificent:
"There is therefore now no condemnation for those who are in Christ Jesus. For the law of the Spirit of life has set you free in Christ Jesus from the law of sin and death... those who live according to the Spirit set their minds on the things of the Spirit... You, however, are not in the flesh but in the Spirit, if in fact the Spirit of God dwells in you... If the Spirit of Him Who raised Jesus from the dead dwells in you, He Who raised Christ Jesus from the dead will also give life to your mortal bodies through His Spirit Who dwells in you... For all who are led by the Spirit of God are sons of God. For you did not receive the spirit of slavery to fall back into fear, but you have received the Spirit of adoption as sons, by Whom we cry, 'Abba! Father!' The Spirit Himself bears witness with our spirit that we are children of God, and if children, then heirs ~ heirs of God and fellow heirs with Christ... The Spirit helps us in our weakness... And we know that for those who love God all things work together for good, for those who are called according to His purpose. For those whom He foreknew He also predestined to be conformed to the image of His Son... And those whom He predestined He also called, and those whom He called He also justified, and those whom He justified He also glorified... we are more than conquerors through Him who loved us... neither death nor life, nor angels nor rulers, nor things present nor things to come, nor powers, nor height nor depth, nor anything else in all creation, will be able to separate us from the love of God in Christ Jesus our Lord."
Since we have been granted these things, as Paul writes to the Philippians, we do most certainly have a great responsibility to live as becomes sons of God and followers of Christ, so we are to
"work out (our)
own salvation with fear and trembling," but this is
because "it is God who works in (us)
... to..." ~
so that we will ~
"...will and work for His good pleasure."
And I'm sure you will remember that Jesus Himself says,
"My sheep hear my voice, and I know them, and they follow me. I give them eternal life, and they will never perish, and no one will snatch them out of my hand. My Father, Who has given them to Me, is greater than all, and no one is able to snatch them out of the Father's hand. I and the Father are one."
Apologies; I didn't mean for this to be this long... :) But I will say this, that since God initially gives us the grace to believe in Him and to turn from self (it is God's kindness/grace that leads us to repentance; Romans 2:4), so it necessarily follows that He also gives us the grace to keep on trusting Him. Therefore. one simply
cannot logically believe that salvation by God's grace ~ which is undeniable ~ and that it is possible to lose salvation through human failure at the same time. If we expect ourselves to maintain our faith and keep everything going, we fall under the reprimand of Paul, as he confronted the Galatian church by saying,
"You foolish Galatians! Who has bewitched you?... Did you receive the Spirit by observing the law, or by believing what you heard? Are you so foolish? After beginning with the Spirit, are you now trying to attain your goal by human effort?" (Galatians 3:1-3).
So. :) So... So, as I said/cited before,
"(T)
he gifts and the calling of God are irrevocable" (Romans 11:29). And as Job finally acknowledges ~ and we should, too, because it's true ~
"(God's)
purposes cannot be thwarted" (Job 42:2).
We worship
such a great and awesome God, do we not? All thanks and glory be unto Him!
Grace and peace to you.