JustHuman: If I change into something else, it's not me anymore. What responsibilty will that 'new me' have towards it's 'old me', regarding that previous life?
I mean, 'me' is who I am.
Of course, ALL who are given an identity and a personage to be born into are both created unique, and will be so eternally. As the rewards (Heaven) and punishments (Hell) of eternity are determined by how we respond to God on earth (whether to Believe and commit to Him, or whether to only forever resist Him), then neither punishment or reward would make sense if such things were applied to a person who becomes (in eternity) someone different from their earthly identity, upon whose actions/responses to God result in whatever rewards or punishments are dished out.
As for the present earth, there is no person identical to any other – now or after death. The Bible teaches that people will remain themselves – they'll just not remain in their old bodies (after death). Jesus referenced those who died believing in God by their specific names – including Abraham, Issac, and Jacob (Matthew 8:11). On the Mount of Transfiguration, in Matthew 17, Moses and Elijah appear before Jesus and Peter – and they had long been physically dead, and yet they were referenced by their names, and Jesus spoke to them. In Matthew 18, at the Great Banquet in Heaven, again, there Abraham and Issac are referenced being there. And do disembodied spirits eat and drink at a banquet???!!!
Heaven is described repeatedly as a physical place, but not as per the present physical realm in which people and things decay and are corrupted (due to sin). When the Apostle John describes the New Jerusalem coming down out of the present Heaven, merging with the New Earth (which is what Heaven will then be), what he details were things that he actually SAW – replete with considerable detail as to their descriptions, and his description of physical activities. ALL believer in Heaven will also receive additional and NEW names (Isaiah 62:2, 65:15, Revelation 2:17, 3:12). The Bible describes NATIONS being in Heaven.
In Heaven, those there will still be themselves, but gloriously transformed, with no further pain, suffering, death, or any further sinful, evil desires – so, people will STILL be humans – albeit saved ones with new and uncorrupted bodies with abilities beyond what we can currently imagine – these are described across Scripture. There will be nations and leaders in Heaven. With the New Jerusalem at its center. JESUS was physically resurrected, and the angels told those watching Him disappear into the clouds that, He “will come again, in the same way as you saw him go into heaven” - meaning, He will, one day, PHYSICALLY return.
Jesus is now FOREVER and ALSO a man – while He's forever been God! Scripture says He is a high priest FOREVER:
"where Jesus has entered as a forerunner for us, having become a high priest forever according to the order of Melchizedek." (Heb. 6:20).
"Hence, also, He is able to save forever those who draw near to God through Him, since He always lives to make intercession for them." (Heb. 7:25).
More on Jesus' eternal HUMANITY, here:
https://carm.org/jesus-is-a-man
JustHuman: An eternity in paradise as... what? What remains of us when we are enlightened? Are 'you' still 'you', or have you become something completely different, like a butterfly from caterpillar?
And why do only 'good' people get that enlightening? It is the 'bad' people that need it most.
Besides that, what are billions of close-to-devine enlightened beings going to do in all that eternity? Eternity isn't a few years, a couple of million years, or even billion of years.
God is unlimited in what He will provide those in Heaven – with constant new and amazing things to discover, created, pursue, new joys – God never quits creating and He offers those in eternity with Him unlimited possibilities – except He has the power to make all things possible, an actuality. But even in Heaven, the greatest joy by far will be the presence of the Lord Himself. We can't imagine that – as we are currently all sinful men, still in fleshly corruption. Think of the most amazing, beautiful and incredible experiences any man can have on earth – it will pale in comparison to the experiences of those living with the Lord in His Heaven! Such is the hope and destiny of ALL who will love the Father/Son/Spirit: GOD!