That's NOT what the LORD told Adam and the woman in Gen 2:
16 And the LORD God commanded the man, “You are free to eat from any tree in the garden;
17 but you must not eat from the tree of the knowledge of good and evil, for when you eat from it you will certainly die.”
Now combine this with Rom 5:12 -
12 Therefore, just as sin entered the world through one man, and death through sin, and in this way death came to all people, because all sinned— and v.14 -
14 Nevertheless, death reigned from the time of Adam to the time of Moses, even over those who did not sin by breaking a command, as did Adam, who is a pattern of the one to come.
That's not the issue at hand. It's the false idea that discipline is used in death.
Is this a suggestion that Paul was in error in 1 Cor 11:30, or chapter 10:
5 Nevertheless, God was not pleased with most of them; their bodies were scattered in the wilderness.
8 We should not commit sexual immorality, as some of them did—and in one day twenty-three thousand of them died.
This is referring to their physical deaths. So what should one call it when people physically die as a result of sin?
Oh, and let's not forget what happened to King Saul in 1 Sam 31:
4 Saul said to his armor-bearer, “Draw your sword and run me through, or these uncircumcised fellows will come and run me through and abuse me.” But his armor-bearer was terrified and would not do it; so Saul took his own sword and fell on it.
5 When the armor-bearer saw that Saul was dead, he too fell on his sword and died with him.
However, this is the summary of Saul's end:
1 Chron 10:
13 Saul died because he was unfaithful to the LORD; he did not keep the word of the LORD and even consulted a medium for guidance,
14 and did not inquire of the LORD. So the LORD put him to death and turned the kingdom over to David son of Jesse.
Still want to argue that physical death isn't part of God's discipline?
To take a person from the issue they need to be disciplined in, to a place that is free from the need of discipline - is by very definition not discipline.
Some failed believers are just taken home. Period.
Earning rewards is a construct of the human mind.
Never mind the extent of biblical teaching on reward based on obedience and faithfulness then.
Only sinless people do go to heaven.
Well then, that would mean no one will ever go to heaven. But this is what the Bible says about that in Rom 3:
9 What shall we conclude then? Do we have any advantage? Not at all! For we have already made the charge that Jews and Gentiles alike are all under the power of sin.
23 for all have sinned and fall short of the glory of God,
and, in 1 John 1:
8 If we claim to be without sin, we deceive ourselves and the truth is not in us.
10 If we claim we have not sinned, we make him out to be a liar and his word is not in us.
God does not allow sinful man in heaven. God is Holy.
Then Jesus would have a problem returning back to heaven:
2 Cor 5:21
God made him who had no sin to be sin for us, so that in him we might become the righteousness of God.
Revelation 21
1 Then I saw a new heaven and a new earth, for the first heaven and the first earth had passed away, and the sea was no more.
2 And I saw the holy city, new Jerusalem, coming down out of heaven from God, prepared as a bride adorned for her husband.
3 And I heard a loud voice from the throne saying, "Behold, the dwelling place of God is with man. He will dwell with them, and they will be his people, and God himself will be with them as their God.
4 He will wipe away every tear from their eyes, and death shall be no more, neither shall there be mourning, nor crying, nor pain anymore, for the former things have passed away."
5 And he who was seated on the throne said, "Behold, I am making all things new." Also he said, "Write this down, for these words are trustworthy and true."
6 And he said to me, "It is done! I am the Alpha and the Omega, the beginning and the end. To the thirsty I will give from the spring of the water of life without payment.
7 The one who conquers will have this heritage, and I will be his God and he will be my son.
8 But as for the cowardly, the faithless, the detestable, as for murderers, the sexually immoral, sorcerers, idolaters, and all liars, their portion will be in the lake that burns with fire and sulfur, which is the second death."
Is your view that v.8 is a list of specific sins that Christ did not die for??