It seems to me you're asking about Eternal Security.
Not at all. Only posting that there is no such thing as eternal security as shown in the scriptures in the OP. Happy to look at your scriptures to see if they say that a BELIEVER cannot depart from God and become an unbeliever as it states in the OP if you like?
"I am persuaded that neither death nor life, nor angels nor principalities nor powers, nor things present nor things to come, nor height nor depth, nor any other created thing, shall be able to separate us from the love of God which is in Christ Jesus our Lord." Rom 8:38,39
Now if "things to come" cannot separate us from the love of Christ, that is by definition eternal security. Furthermore while there are those who allege we can separate ourselves, such is not the case given that the list includes "any other created thing". Are you a created thing? Well then you cannot separate yourself.
Love the scriptures here and I believe them. Sadly they do not support your interpretation of them. Your argument here is that a "BELIEVER" once saved cannot be lost or unsaved. The scriptures here say no such thing. Notice that the promises here are CONDITIONAL in relation to "US" which is in reference to "BELIEVERS" in the "PRESENT TENSE". These scriptures are in reference to "BELIEVERS" that are BELIEVING and FOLLOWING God's WORD in the now. They do not say a BELIEVER cannot depart from God's WORD. They say that no one can separate God's LOVE from BELIEVERS. If we BELIEVE and FOLLOW God's WORD than God's promises are for us. If we are not BELIEVING and FOLLOWING God's WORD then God's promises are not for UNBELIEVERS. Sadly UNBELIEVERS have no part in God's Word.
Furthermore those who belong to Christ don't fall away, as it is written in 1John 2:19 They went out from us, but they did not really belong to us. For if they had belonged to us, (ONCE SAVED) they would have remained with us; (ALWAYS SAVED) but their going showed that none of them belonged to us.
Nope! No where God's WORD does it state anywhere that believers do not FALL AWAY. In fact we read that BELIEVERS can indeed fall away and we as Christians are WARNED in God's WORD not to.
2 THESSALONIANS 2:3-4
Let no one deceive you by any means; for that Day will not come unless the
FALLING AWAY comes first, and the man of sin is revealed, the son of perdition, who opposes and exalts himself above all that is called God or that is worshiped, so that he sits as God in the temple of God, showing himself that he is God.
2 THESSALONIANS 2:9-10
The coming of the lawless one is according to the working of Satan, with all power, signs, and lying wonders, and with all unrighteous deception among those who perish,
BECAUSE THEY DID NOT RECEIVE THE LOVE OF THE TRUTH THAT THEY MIGHT BE SAVED.
HEBREWS 6:4-8
[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 to repentance; seeing they crucify to themselves the Son of God afresh, and put him to an open shame.
[7], For the earth which drinks in the rain that comes oft on it, and brings forth herbs meet for them by whom it is dressed, receives blessing from God:
[8], But that which bears thorns and briers is rejected, and is near to cursing;
whose end is to be burned.
2 PETER 2:20-22
[20],
FOR IF THEY HAVE ESCAPED THE POLLUTIONS OF THE WORLD THROUGH THE KNOWLEDGE OF THE LORD AND SAVIOUR JESUS CHRIST, THEY ARE AGAIN ENTANGLED THEREIN AND OVERCOME, THE LATTER END IS WORSE THEN THE BEGGINING.
[21],
FOR IT HAD BEEN BETTER FOR THEN NOT TO HAVE KNOWN THE WAY OF RIGHTEOUSNESS, THAN, AFTER THEY HAVE KNOWN IT, TO TURN FROM THE HOLY COMMANDMENT DELIEVERED UNTO THEM.
[22],
But it is happened to them according to the true proverb, The dog is turned to his own vomit again; and the sow that was washed to her wallowing in the mire.
Yep seems Peter thinks that you can know and follow God and then turn back from God to follow SIN and leave God....
links to....
HEBREWS 10:26-31
[26], FOR IT WE SIN WILLFULLY
AFTER WE RECEIVE A KNOWLEDGE OF THE TRUTH, THERE REMAINS NO MORE SACRIFICE FOR SINS,
[27], BUT A FEARFUL LOOKING FORWARD FOR OF JUDGEMENT AND FIERY INDIGNATION, WHICH SHALL DEVOUR THE ADVERSARIES.
[28], He that despised Moses' law died without mercy under two or three witnesses:
[29],
OF HOW MUCH MORE SORER PUNISHMENT, SUPPOSE YOU, SHALL HE BE THOUGHT WORTHY, WHO HAS TRODDEN UNDER FOOT THE SON OF GOD, AND HAS COUNTED THE BLOOD OF THE COVENANT WITH WHICH HE WAS SANCTIFIED AN UNHOLY THING AND HAS DONE DESPITE TO THE SPIRIT OF GRACE?
[30], For we know him that has said, Vengeance belongs to me, I will recompense, said the Lord. And again, The Lord shall judge his people.
[31], IT IS A FEARFUL THING TO FALL INTO THE HANDS OF THE LIVING GOD.
GALATIANS 1:6
[6] I marvel that you are
TURNING AWAY SO SOON from Him who called you in the grace of Christ,
TO A DIFFERENT GOSPEL.
ACTS 20:28-31
Therefore take heed to yourselves and to all the flock, among which the Holy Spirit has made you overseers, to shepherd the church of God which He purchased with His own blood. For I know this, that after my departure savage wolves will come in among you, not sparing the flock. Also from among yourselves men will rise up, speaking perverse things,
TO DRAW AWAY DISCIPLES AFTER THEMSELVES. Therefore watch, and remember that for three years I did not cease to warn everyone night and day with tears.
HEBREWS 2:1-3
Therefore we must give the more earnest heed to the things we have heard,
LEST WE DRIFT AWAY. For if the word spoken through angels proved steadfast, and every transgression and disobedience received a just reward, how shall we escape if we neglect so great a salvation, which at the first began to be spoken by the Lord, and was confirmed to us by those who heard Him.
HEBREWS 10:35-38
[35],
CAST NOT AWAY THEREFORE YOUR CONFIDENCE, which has great recompense of reward. [36], For you have need of patience, that,
after you have done the will of God, you might receive the promise. [37], For yet a little while, and he that shall come will come, and will not tarry. [38], Now the just shall live by faith:
BUT IF ANY MAN SHALL DRAW BACK, my soul shall have no pleasure in him.
Seems both PAUL and PETER agree together that you can KNOW GOd have a KNOWLEDGE of the TRUTH and fall away back into SIN.
ISAIAH 59:1-3
[1], Behold, the LORD's hand is not shortened, that it cannot save; neither his ear heavy, that it cannot hear:
[2],
BUT YOUR INIQUITIES HAVE SEPARATED BETWEEN YOU AND YOUR GOD, AND YOUR SINS HAVE HID HIS FACE FROM YOU THAT HE WILL NOT HEAR.
[3], For your hands are defiled with blood, and your fingers with
SIN; your lips have spoken lies, your tongue has muttered perverseness.
Seems Isaiah agrees with Peter and Paul that SIN can separate us from GOD.
EZEKIEL 3:17-21
[17]
, Son of man, I have made you a watchman to the house of Israel: therefore hear the word at my mouth, and give them warning from me.
[18], When I say to the wicked, You shall surely die; and you give him not warning, nor speak to warn the wicked from his wicked way, to save his life; the same wicked man shall die in his iniquity; but his blood will I require at your hand.
[19], Yet if you warn the wicked, and he turn not from his wickedness, nor from his wicked way, he shall die in his iniquity; but you have delivered your soul.
[20]
, AGAIN,
WHEN A RIGHTEOUS MAN DOES TURN FROM HIS RIGHTEOUSNESS, AND COMMIT INIQUITY, AND I LAY A STUMBLING BLOCK BEFORE HIM, HE SHALL DIE IN HIS SIN, AND HIS RIGHTEOUSNESS WHICH HE HAS DONE SHALL NOT BE REMEMBERED; but his blood I will require from your hand.
[21], Nevertheless if you warn the righteous man, that the righteous sin not, and he does not sin, he shall surely live, because he is warned; also you have delivered your soul.
Well there we have it Ezekial, Isaiah Peter and Paul all agree that you can know God and have a KNOWLEDGE of the TRUTH and fall away back into SIN.
JOSHUA 23:11-13
[11], Take good heed therefore to yourselves, that you love the LORD your God.
[12],
ELSE IF YOU IN ANY WISE GO BACK TO JOIN TO THE REMNANNT OF THESE NATIONS, EVEN THESE THAT REMAIN AMONG YOU AND SHALL MAKE MARRIAGES WITH THEM AND GO IN UNTO THEM AND THEY TO YOU:
[13], KNOW FOR A CERTAINTY THAT THE LORD YOUR GOD WILL NO MORE DRIVE OUT THESE NATIONS FROM BEFORE YOU.; but they shall be snares and traps to you, and scourges in your sides, and thorns in your eyes, until you perish from off this good land which the LORD your God has given you.
Now Joshua is joining Ezekial, Isaiah Peter and Paul who all agree that you can know God and have a KNOWLEDGE of the TRUTH and fall away back into SIN.
NUMBERS 14:43
[43], For there the Amalekites and the Canaanites are facing you, and you shall fall by the sword.
BECAUSE YOU HAVE TURNED BACK FROM FOLLOWING THE LORD,
THE LORD WILL NOT BE WITH YOU.”
Now you can also add Moses to Joshua, Ezekial, Isaiah, Peter and Paul who all agree that you can know God and have a KNOWLEDGE of the TRUTH and fall away back into SIN.
JAMES 5:19
[19], My brothers,
IF ANY AMONG YOU WANDERS FROM THE TRUTH AND SOMEONE BRINGS HIM BACK, let him know that
whoever brings back a sinner from his wandering will save his soul from death and will cover a multitude of sins.
Seems also James agrees with Moses, Joshua, Ezekial, Isaiah, Peter and Paul who all agree that you can know God and have a KNOWLEDGE of the TRUTH and fall away back into SIN.
JEREMIAH 3:8-14
[8], And I saw, when for all the causes whereby
backsliding Israel committed adultery I had put her away, and given her a bill of divorce; yet her treacherous sister Judah feared not, but went and played the harlot also.
[9], And it came to pass through the lightness of her prostitution, that she defiled the land, and committed adultery with stones and with stocks.
[10], And yet for all this her treacherous sister Judah
has not turned to me with her whole heart, but feignedly, said the LORD.
[11],
And the LORD said to me, The backsliding Israel has justified herself more than treacherous Judah.
[12], Go, and proclaim these words toward the north, and say,
RETURN FAITHLESS ISRAEL, declares the Lord. I will not look on you in anger, for I am merciful, declares the Lord; I will not be angry forever.
[13],
Only acknowledge your iniquity,
that you have transgressed against the LORD your God, and have scattered your ways to the strangers under every green tree, and you have not obeyed my voice, said the LORD.
[14],
TURN O BACKSLIDING CHILDREN, said the LORD; for I am married to you: and I will take you one of a city, and two of a family, and I will bring you to Zion.
Looks like we can add Jeremaiah to James, Moses, Joshua, Ezekial, Isaiah, Peter and Paul who all agree that you can know God and have a KNOWLEDGE of the TRUTH and fall away back into SIN.
JOEL 2:13
[13], And rend your hearts and not your garments.
RETURN TO THE LORD YOUR GOD, for he is gracious and merciful, slow to anger, and abounding in steadfast love; and he relents over disaster.
LUKE 8:13
[13], They on the rock are they, which, when they hear,
receive the word with joy; and these have no root, which for a while believe, and in time of temptation FALL AWAY.
Well here so far we have Joel, Jeremaiah, James, Moses, Joshua, Ezekial, Isaiah, Peter, Luke and Paul who all agree that you can know God and have a KNOWLEDGE of the TRUTH and FALL AWAY back into SIN.
................
CONCLUSION: We can GREIVE God's Spirit if we continue in known unrepentant sin and he will depart from us and leave us over to strong delusions if we do not receive and love the truth.
Now where in the scripture you quoted above in 1 JOHN 2:19 does it say a Christian is once saved always saved and cannot fall away? It doesn't does it? Let's look at your foundation scripture that you interpret to support once saved always saved in detail as the scripture you provide here only support all the othere provided above warning God's poeple not to fall away and depart from the faith...
1 JOHN 2:18-19
[18], Little children, it is the last time: and as you have heard that antichrist shall come, even now are there many antichrists; whereby we know that it is the last time.
[19], They went out from us, but they were not of us;
for if they had been of us, they would no doubt have continued with us: but they went out, that they might be made manifest that they were not all of us.
What did they go out from? Yep you guessed it. They went out from the truth. It was going out and leaving the truth that made these people not of us as leaving God's truth made them "UNBELIEVERS". The CONTEXT is that there is many antichrists and false teachers. They went out from the truth of God's Word and no longer believed and followed Gods' Word which made them not of us (Believers and followers of Gods' Word).
If they contunued with us then they would be continuing to believe and follow the truth of God's Word and would have been of us.
The reason they don't as explained in 1John 3:9 is due to the regenerate nature.
"No one who is born of God will continue to sin, because God’s seed remains in him; he cannot go on sinning, because he has been born of God."
And as you noted we're sealed for the day of redemption. Like verses say:
"Now it is God who makes both us and you stand firm in Christ. He anointed us, He set his seal of ownership on us, and put his Spirit in our hearts as a deposit, guaranteeing what is to come." 2Cor 1:21,22
"And you also were included in Christ when you heard the word of truth, the gospel of your salvation. Having believed, you were marked in him with a seal, the promised Holy Spirit, who is a deposit guaranteeing our inheritance until the redemption of those who are God’s possession— to the praise of his glory." Eph 1:13,14
All such rhetoric is consistent with the concept of Eternal Security.
Once agian love the scriptures and I believe them. Sadly they do not support your interpretation of them suggesting and application of once saved always saved or a "BELIEVER" once saved cannot be lost and turn away from God and be unsaved. The scriptures here say no such thing.
The application here is to "BELIEVERS" in the "PRESENT TENSE". These scriptures are in reference to "BELIEVERS" that are BELIEVING and FOLLOWING God's WORD. They do not say a BELIEVER cannot depart from God's WORD now do they.
...........
Sorry brother you have not provided a single scripture that supports once saved always saved. According to God's WORD it is only he who endures to the end that will be saved *MATTHEW 10:22. Seems many are going to be disappointed come judgment day.
Hope this helps
.