Those who peddle salvation by works typically cite all the same passages of scripture that you continue to cite. Those who are truly born of God have received a new nature, a divine nature. They have been transformed from pigs and dogs into sheep. The change is more than just cosmetic, as in 2 Peter 2:20. *These cleaned up on the outside dogs and pigs were never sheep.*
Compare 2 Peter 1:4 - "partakers of the divine nature, having escaped the corruption - Strongs #5356 that is in the world through lust" with 2 Peter 2:20 - with they escaped the pollutions - Strongs #3356 (different Greek word) of the world through the knowledge of the Lord and Saviour Jesus Christ, yet they are again entangled therein, and overcome. *Notice that 2 Peter 2:20 did not mention them being "partakers of the divine nature."
Corruption (Strongs #5356) (to shrivel or wither, spoil , ruin , deprave, corrupt , defile, to destroy by means of corrupting, to spoil as does milk). Corruption - describes decomposition or rotting of an organism and the accompanying stench. The utter depravity of the fallen flesh and the resultant moral decomposition of the world opposed to God is driven by it sinful lusts or evil desires. Internal corruption.
Pollutions/Defilements (Strongs #3393) ("pollutions", "filthy things", "contaminations", "world's filth") describes the state of being tainted or stained by evil and refers to impurity, impure, tainted, defilement, foulness or pollution. Pollutions/Defilement refers to what is on the outside (2 Peter 2:20). But genuine believers have escaped the corruption that is in the world through lust (2 Peter 1:4).
Corruption is deeper than pollutions/defilements on the outside: it is decay on the inside. Having the knowledge of Jesus Christ does not save a person if there is no heart submission to that knowledge. The latter end is worse than the beginning for these men because rejecting this knowledge will make them more accountable at the judgment.
*Notice - Brethren, if anyone "among" you wanders from the truth..turns a "sinner" from the error of his way.. Some would argue that James says this one who turned from the truth was a "sinner," and was "among" but "not of" the Brethren, then he wasn’t previously saved. That fits 1 John 2:19 - They went out "from" us, but they were "not of" us..
IF this person was a genuine believer, yet how do we know for sure this is the second death in the lake of fire? In Matthew 26:38, Jesus said: "My soul [psuche] is deeply grieved, to the point of death." Jesus was not saying that His soul was deeply grieved to the point of spiritual death, Rather, Jesus was talking about physical death, his human life. In Revelation 16:3, "The second angel poured out his bowl into the sea, and it became blood like that of a dead man; and every living soul [psuche] in the sea died".
"Soul" is rendered from the Greek word "psuche" and is also translated as "life". The word "psuche" is never translated as "spirit." In 1 Corinthians 5:5, we read - I have decided to deliver such a one to Satan for the destruction of his flesh, so that his spirit may be saved in the day of the Lord Jesus (no second death).
Jesus covered our sins in one way (Romans 4:7) by bringing forgiveness for all believers, yet sins can also be covered in a different way. In Proverbs 10:12, we read: Hatred stirs up strife, But love covers all sins. In 1 Peter 4:8, we read: And above all things have fervent love for one another, for "love will cover a multitude of sins." Where there is strife, there is hatred and unless love prevails, the strife will get worse. Love covers offenses and sins when a believer turns back from error.
So is this wanderer a professing Christian, whose faith is not genuine, or a sinning Christian, who needs to be restored? For the former, the death spoken of in vs. 20 is the "second death" (Revelation 21:8); for the latter, it is physical death (1 Corinthians 11:29-32; 1 John 5:16).
Enduring to the end is descriptive of those who are truly born of God. Psalm 37:28 - For the Lord loves justice, And does not forsake His saints; They are preserved forever, But the descendants of the wicked shall be cut off.
Where does the text say, "fallen brother?" You are reading your own preconceived theology into the text. The fact that this man is called a "servant" does not necessarily mean that he was saved.
The Jews were called the Lord’s servants, but they were not all saved. *Isaiah 43:10 - "You are My witnesses, says the Lord," And My servant whom I have chosen, That you may know and believe Me, And understand that I am He. Before Me there was no God formed, Nor shall there be after Me.
*Leviticus 25:55 - For the children of Israel are servants to Me; they are My servants whom I brought out of the land of Egypt: I am the Lord your God. Yet God later destroyed those who did not believe. (Jude 1:5)
*Nehemiah 1:6 - please let Your ear be attentive and Your eyes open, that You may hear the prayer of Your servant which I pray before You now, day and night, for the children of Israel Your servants, and confess the sins of the children of Israel which we have sinned against You. Both my father’s house and I have sinned.
Proverbs 24:16 - For a righteous man may fall seven times And rise again, But the wicked shall fall by calamity.
Ezekiel 18:29 - But the house of Israel says, 'The way of the Lord is not right.' Are My ways not right, O house of Israel? Is it not your ways that are not right? But the house of Israel says, 'The way of the Lord is not right.' Are My ways not right, O house of Israel? Is it not your ways that are not right? Ezekiel 33:13 - When I say to the righteous that he shall surely live, but he trusts in his OWN righteousness and commits iniquity, none of his righteous works shall be remembered; but because of the iniquity that he has committed, he shall die.
Did you read that? "If he trusts in his OWN RIGHTEOUSNESS." This is the heart of the matter here. This is describing a righteousness which is by the law rather than that which is by faith. The New Testament states in Romans 10:3 - "For they being ignorant of God's righteousness, and going about to establish their OWN RIGHTEOUSNESS, have not submitted themselves unto the righteousness of God. 4 For Christ is the end of the law for righteousness to every one that BELIEVES.
As James Fawcett Brown points out - righteous--one apparently such; as in Matthew 9:13, "I came not to call the righteous," that is, those who fancy themselves righteous. First please notice the underlined words "his righteousness" meaning that the "righteous" turns from his righteousness. That is his OWN righteousness.
SALVATION OBTAINED BY WORKS/SALVATION MAINTAINED BY WORKS WILL CAUSE MANY MANY MANY TO BE LOST.