You are picking a fight with a strawman argument.
Jesus is emphatic in telling us that those who persevere will inherit the Kingdom of God. As does St. Paul.
Neither never says, Once saved, always saved.
People can, and do, sin even after Baptism.
And, no one who is unclean from sin can enter into the Kingdom.
If you die with sin staining your soul, in your view you are doomed. And most people DO die with sin staining their soul.
Please don’t judge people so harshly. Peace
Christ has removed our sin as far as the east from the west. Therefore there is no condemnation for those in Christ Jesus. I guess it all boils down to if you believe Cbrists saving work is sufficient or not. If you think it is not where will you find salvation. In your own suffering and feeble attempts to atone? I think not
The verses about persevering are referring to surviving the Tribulation period, not the church age believers.
Neither never says, Once saved, always saved.
Security of the believer
John 5:24 Truly, truly, I say to you, whoever hears my word and believes him who sent me has eternal life. He does not come into judgment, but has passed from death to life.
John 6:37-39 All that the Father gives me will come to me, and whoever comes to me I will never cast out. For I have come down from heaven, not to do my own will but the will of him who sent me. And this is the will of him who sent me, that I should lose nothing of all that he has given me, but raise it up on the last day.
John 10:25-30 Jesus answered them, “I told you, and you do not believe. The works that I do in my Father's name bear witness about me, but you do not believe because you are not among my sheep. 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.”
Romans 4:16 Therefore, the promise comes by faith, so that it may be by grace and may be guaranteed to all Abraham's offspring-not only to those who are of the law but also to those who have the faith of Abraham. He is the father of us all.
1 Corinthians 1:4-8 I give thanks to my God always for you because of the grace of God that was given you in Christ Jesus,that in every way you were enriched in him in all speech and all knowledge—even as the testimony about Christ was confirmed among you—so that you are not lacking in any gift, as you wait for the revealing of our Lord Jesus Christ, who will sustain you to the end, guiltless in the day of our Lord Jesus Christ.
2 Corinthians 1:21-22 And it is God who establishes us with you in Christ, and has anointed us, and who has also put his seal on us and given us his Spirit in our hearts as a guarantee.
2 Corinthians 5:4-8 For while we are still in this tent, we groan, being burdened—not that we would be unclothed, but that we would be further clothed, so that what is mortal may be swallowed up by life. He who has prepared us for this very thing is God, who has given us the Spirit as a guarantee.
So we are always of good courage. We know that while we are at home in the body we are away from the Lord, for we walk by faith, not by sight. Yes, we are of good courage, and we would rather be away from the body and at home with the Lord.
Ephesians 1:13-14 In him you also, when you heard the word of truth, the gospel of your salvation, and believed in him, were sealed with the promised Holy Spirit, who is the guarantee of our inheritance until we acquire possession of it, to the praise of his glory.
There are many more verses if those aren't enough for you.
It's not a matter of just staining the soul. The penalty for sin is death. period.
The born again believer has been born again/born from above by the Holy Spirit with a new spiritual nature that is sinless.
When we die, the sin nature is gone for good and what remains is the new, pure spirit that the Holy Spirit gave us.
There is no sin *staining* that nature.
That's why Paul can say that to be absent from the body is to be present with the Lord. No purgatory.
Additionally, the born again believer is already positionally in heaven with Christ.
Ephesians 2:4-7 But God, being rich in mercy, because of His great love with which He loved us, even when we were dead in our transgressions, made us alive together with Christ (by grace you have been saved), and raised us up with Him, and seated us with Him in the heavenly places in Christ Jesus, so that in the ages to come He might show the surpassing riches of His grace in kindness toward us in Christ Jesus.
A person who dies with sin on their account, goes to hell. NO matter what the sin is and no amount of suffering anywhere can cleanse it because without the shedding of blood, there is no forgiveness of sin. Suffering is not cleansing with the blood of Jesus.
Hebrews 9:22 Indeed, under the law almost everything is purified with blood, and without the shedding of blood there is no forgiveness of sins.
The believer has a judicial pardon from heaven that cleans expunges his record of sin. It has been dealt with and was paid for by Jesus. It doesn't have to be paid twice swhich is what suffering in purgatory is.
Colossians 2:13-15 And you, who were dead in your trespasses and the uncircumcision of your flesh, God made alive together with him, having forgiven us all our trespasses, by canceling the record of debt that stood against us with its legal demands. This he set aside, nailing it to the cross.
He disarmed the rulers and authorities and put them to open shame, by triumphing over them in him.
Colossians 2:16-23 Therefore let no one pass judgment on you in questions of food and drink, or with regard to a festival or a new moon or a Sabbath. These are a shadow of the things to come, but the substance belongs to Christ. Let no one disqualify you, insisting on asceticism and worship of angels, going on in detail about visions, puffed up without reason by his sensuous mind, and not holding fast to the Head, from whom the whole body, nourished and knit together through its joints and ligaments, grows with a growth that is from God.
If with Christ you died to the elemental spirits of the world, why, as if you were still alive in the world, do you submit to regulations— “Do not handle, Do not taste, Do not touch” (referring to things that all perish as they are used)—according to human precepts and teachings? These have indeed an appearance of wisdom in promoting self-made religion and asceticism and severity to the body, but they are of no value in stopping the indulgence of the flesh.
Roman Catholic (the Eastern Orthodox tend to reject the Roman version) Purgatory is based upon a false premise, not only that there is a need for further atonement for some sins after death, but that justification is on the basis of actual righteousness, which is first attained via the act itself of baptism (and which for infants means without even having to repent and to believe on the Lord Jesus with all their heart, which is contrary to Acts 2:38; 8:36,37; 10:43–47- 15:7–9) effecting "infused” righteousness, for in RC theology one is formally justified by their own righteousness. (Catholic Encyclopedia>Sanctifying Grace)
However, since since the unholy sin nature remains, then after baptism unless the baptized is one of the very few who has become perfect in character in this life and dies in that state, then entering Heaven can only be attained by attaining perfection of character ("by grace") thru postmortem “purifying punishments” and sufferings, commencing at death, in order to be with God.