Again, I believe you know this - but according to your choice of words, once again:
You left out the key words: IN CHRIST
When we are indwelt with the Holy Spirit we are in Christ, and He in us.
Matthew 12:18 (KJV) Behold my servant, whom I have chosen; my beloved, in whom my soul is well pleased: I will put my spirit upon him, and he shall shew judgment to the Gentiles.
Acts 2:17 (KJV) And it shall come to pass in the last days, saith God, I will pour out of my Spirit upon all flesh: and your sons and your daughters shall prophesy, and your young men shall see visions, and your old men shall dream dreams:
John 15:4 (KJV) Abide in me, and I in you. As the branch cannot bear fruit of itself, except it abide in the vine; no more can ye, except ye abide in me.
No seed of created human beings has ever ascended to heaven - nor could we or can they - only Christ has ascended to heaven - from whence He had descended. So again you left out the key words: IN CHRIST
Paul tells us when are absent from the body we are present with the Lord in heaven, that where He is we shall be also. We do not ascend to heaven as human beings, rather we ascend to heaven a spiritual body, living souls without human form through Christ's Holy Spirit in us.
2 Corinthians 5:8 (KJV) We are confident, I say, and willing rather to be absent from the body, and to be present with the Lord.
Philippians 1:20-24 (KJV) According to my earnest expectation and my hope, that in nothing I shall be ashamed, but that with all boldness, as always, so now also Christ shall be magnified in my body, whether it be by life, or by death. For to me to live is Christ, and to die is gain. But if I live in the flesh, this is the fruit of my labour: yet what I shall choose I wot not. For I am in a strait betwixt two, having a desire to depart, and to be with Christ; which is far better: Nevertheless to abide in the flesh is more needful for you.
John 12:26 (KJV) If any man serve me, let him follow me; and where I am, there shall also my servant be: if any man serve me, him will my Father honour.
John 14:2-4 (KJV) In my Father's house are many mansions: if it were not so, I would have told you. I go to prepare a place for you. And if I go and prepare a place for you, I will come again, and receive you unto myself; that where I am, there ye may be also. And whither I go ye know, and the way ye know.
The created human beings - Adam and Eve - did not eternally possess eternal life in themselves
I agree, man may only possess eternal spiritual life when they are indwelt with the life giving Spirit of Christ in us. We have assurance this eternal spiritual life will never end, so when our mortal body dies, as spiritual body we ascend to heaven living souls where we wait for the Kingdom of God in heaven to be complete. I believe A&E were covered by the blood of Christ, via promise, the Lamb slain from before the foundation of the world. When they disobeyed God their eyes were opened, a spiritual picture of knowing they had sin against God. They tried to hide their nakedness without God because guilt made them realize what it meant to be naked before Him. Through grace God made them coats of skins, and clothed them, symbolizing righteousness through the blood of the Lamb of God.
Genesis 3:7 (KJV) And the eyes of them both were opened, and they knew that they were naked; and they sewed fig leaves together, and made themselves aprons.
Genesis 3:21 (KJV) Unto Adam also and to his wife did the LORD God make coats of skins, and clothed them.
Their life after receiving mercy from God's demonstrates IMO forgiveness of their sin. One son Abel proved to be righteous before God, which is evidence A&E has instructed them in the ways of God. The other son Cain demonstrates that from the fall through disobedience, sin and death through sin are still the consequence for all mankind, even though God forgives sin.
When God gave A&E another son to replace the one Cain killed called Seth. And in the days of Seth man began to call upon the name of the Lord. Certainly this is the result of A&E raising them up in the way they should go, teaching them to be righteous and obedient to God.
Genesis 4:25 (KJV) And Adam knew his wife again; and she bare a son, and called his name Seth: For God, said she, hath appointed me another seed instead of Abel, whom Cain slew.
Genesis 4:26 (KJV) And to Seth, to him also there was born a son; and he called his name Enos: then began men to call upon the name of the LORD.
IMO this is how we can know with certainty that A&E believed in God and through promise of the One Who would come to crush the serpent they possessed eternal life according to promise, and in death waited for Him to come to redeem them by His Spirit. They believed God and it was accounted unto them as righteousness.
Life never becomes something we ourselves possess in ourselves
Man, never possesses eternal life in ourselves. Man is created with body + the breath of life (spirit) and became a living soul. Through the breath of life (natural spirit) that every living breathing creature upon this earth possesses, man became living soul with physical body through natural birth (spirit). We must make a distinction between that which is of mankind naturally through physical birth, and that which comes to man supernaturally through the Spirit of Christ through supernatural birth from above. Only that spirit in mankind that possesses the Holy Spirit of Christ has eternal life. All who remain living souls with body and natural spirit are destined to die.