My option #2 was:
(2) Teach that God will chasten and discipline the believer who is faltering, but if necessary will kill him (the sin unto death) before he becomes an unbeliever
You said: "Only #2 is correct".
That is correct.
So if you want to get to heaven really fast, just start sinning like Hitler, and God will kill you!??
Are you really that naive about God's discipline towards His disobedient children?
Ever heard of Ananias and Saphira?
Acts 5-
4 Didn’t it belong to you before it was sold? And after it was sold, wasn’t the money at your disposal? What made you think of doing such a thing? You have not lied just to human beings but to God.”
5 When Ananias heard this,
he fell down and died.
And great fear seized all who heard what had happened.
9 Peter said to her, “How could you conspire to test the Spirit of the Lord? Listen! The feet of the men who buried your husband are at the door, and they will carry you out also.”
10
At that moment she fell down at his feet and died. Then the young men came in and, finding her dead, carried her out and buried her beside her husband.
Sometimes the discipline unto death isn't just to take out a disobedient child of God, it's to get the attention of the whole church, as the red words show.
Ever heard of the incestuous believer?
1 Cor 5-
1 It is actually reported that there is sexual immorality among you, and of a kind that even pagans do not tolerate: A man is sleeping with his father’s wife.
5 hand this man over to Satan for
the destruction of the flesh, (physical death at the hand of Satan) so that his spirit may be saved on the day of the Lord.
Ever heard of the Exodus generation? They were all saved.
1 Cor 10-
1 For I do not want you to be ignorant of the fact, brothers and sisters, that our ancestors were all under the cloud and that they all passed through the sea.
2 They were all baptized into Moses in the cloud and in the sea.
3 They
all ate the same spiritual food
4 and
drank the same spiritual drink; for
they drank from the spiritual rock that accompanied them, and that rock was Christ.
5 Nevertheless, God was not pleased with most of them;
their bodies were scattered in the wilderness.
Black bolded words prove that the Israelites were saved.
Red words refer to the sin unto death.
And, for the same reason as for Ananias and Saphira:
11
These things happened to them as examples and were written down
as warnings for us, on whom the culmination of the ages has come.
What is not clear about v.11?
I could go on and on. God's discipline is real. It's painful (Heb 12:11), and it can include physical death, even at the hand of Satan (1 Cor 1:5).
Speaking of which, consider 1 Tim 1-
19 holding on to faith and a good conscience, which some have rejected and so have suffered shipwreck with regard to the faith.
20 Among them are Hymenaeus and Alexander, whom
I have handed over to Satan to be taught not to blaspheme.
If pastors all across this country taught about God's divine discipline, I think the lot of evangelicalism would be vastly improved.