If you think I have evidence from the cosmos that Heaven and the afterlife exist you might be disappointed to find I claim that the evidence is only really there in the mind of a believer in God.
I think believing in God leads to believing in an afterlife and a Heaven because the belief itself involves suffering in this life. I explained before how believers get pressure from society because they themselves as believers become the evidence others need in order to believe. Add to this the bad behaviour of people who don't quite believe but recognise faith in those who do and get in that faith a glimmer of what they are missing and possibly need. They might also get a feeling that the faith proves that they will be judged and this means they might be all the more inclined to take action against believers. So there is curiosity from others as soon as your belief is enough to be noticed. And noticed it must be because it is evidence of God's existence.
Now this suffering does not make sense, given that the faith is not only that God exists but that He is good and He is love. Something is missing: This logical conclusion is taken as proven by the believer because it rests on certainties about God. God rewards faith and is good and is love. Faith does not get rewarded by the world around the believer because it results mainly in suffering (even if just the suffering of extra, perhaps unwanted attention and some ill-feeling along with it, from those who don't believe). So the believer concludes that it is proven therefore that believing in God MUST result in reward in life after this world and its life are gone - after death and outside of this world. 'QED' (QED is a statement made at the end of some ancient Greek mathematical proofs). But QED to a believer. The Apostle Paul wrote to the effect "if there is no resurrection and we are rewarded in this life only then we are of all men most to be pitied". It isn't as rewarding, given that God does exist and does reward faith, sufficiently in this life alone to believe.
Once it is accepted that God is proven to exist and, by the same evidence of His existence, that He is good and loving (as testified by the Christ and seen in the Christ's coming two thousand years ago), then it follows that if there is no reward in this life there must be another life for the reward; hence Heaven, the afterlife ... and even the Resurrection. The Resurrection follows particularly from the testimony of Jesus which is believed and held to by many a believer in God. It is based on the belief that Jesus was Himself proven by God to be the Christ, God's Anointed One, by His resurrection from the dead after He was crucified around 25AD and this after He had promised to many that He would also raise from the dead all who believed in Him. This would be at some point in the future when He returned to Earth in power, "coming in the clouds of Heaven".
Heaven as a place is a bit different. It was often understood in Scripture as a region somewhere above the clouds of the Earth. The region below the clouds was called 'the Air' (of course that is just an English translation) while the region containing the clouds and above was called 'the Heavens' or 'Heaven'.
Note: Some regions within the heavenly region were described a little, for example the Book of Enoch describes a place whose appearance was like an immense hall of crystal (crystal appearance - my interpretation) through which lightnings travel back and forth. Some mention in prophesies is given to a throne of God surrounded by light like an emerald rainbow. To me the descriptions allude to something like the northern and southern lights, something near earth but cosmic in splendour. I would conjecture such descriptions might point to a special part of the outer atmosphere of Earth and some possible candidates seem to exist in the science books, mostly recent findings. I wouldn't discount these candidates adding that angel beings inhabit places above the clouds just as ghosts inhabit deserted places on Earth; if you accept the existence of spirits in general and believe the prophesies and Jesus' testimony.
So the clouds themselves are associated in Scriptures with 'Heaven', especially the space above them, immediately above them. Hebrew Psalms illustrate the use of the term translated 'the Heavens'. "Oh that You would rend the Heavens and come down... send forth your lightning and scatter my enemies." "The Heavens were opened." The Christian Gospels illustrate terms translated 'Heaven'. "A voice came from Heaven 'You are my beloved Son, in whom I am well pleased'... Some said that it thundered." "He went up into Heaven and a cloud hid Him from their sight." "'This same Jesus will so come in like manner as you have seen Him ascend into Heaven.'" The 'atmosphere' is a modern term which is probably equivalent but there was no sense in which what we call 'outer space' was necessarily excluded from the region called 'Heaven', it was merely emphasised that Heaven was from the clouds and upwards.
The fact that terms existed for this region around the Earth (whether or not those using the terms knew the Earth was a sphere) above the clouds and a separate term existed for the region between the clouds and the ground (sometimes translated 'the Air') is not really in question, I would guess. Rather the association is made over thousands of years of religious expression between these regions and spiritual beings and their domains - their Kingdoms. This is where some believe, others doubt and others don't believe at all.
The testimony of those who have believed such as prophets and psalmists has much emphasis on associating the region of the clouds and above with the domain and territory of the Creator of all the regions.
