There is a story that Narad Muni was once sent to the earth from heaven by Lord Indra to fetch water. This was also to teach Narad the lesson in powers of Maya. Narad on coming to earth met and fell in love with a maiden and lived with her and their children for 12 years, before a revelation regarding his true identify was revealed. He went back to Indra who told him that he was gone only for an hour of heaven time. That was Indra's relativity!
Similarly Adi Shankracharya was once engaged in a debate by a Mishra couple who challenged him that being an ascetic monk he does not know anything about love and householder life and concerns. He was stung by the criticism and decided to learn about it. He left his body by yogic powers and entered the body of a recently dead king and enjoyed the company of his beautiful queens for 7 years and would have continued to do so before his friends brought him back to his "senses" and his original body. He understood the power of Maya first hand!
In every religion getting into Maya Jaal or web of love is frowned upon. They all insist that renunciation, breaking of bonds etc., frees the soul for ultimate salvation and liberation. But liberation from what? All religions insist that we should liberate ourselves from the human bonds so that we can become free and merge into Universal Consciousness. Some religions even preach that one reaches heaven after death where all the goodies are available round the clock forever! But isn't this earth of ours that we call home with all its happiness and pain not a part of Universal Consciousness?
What is the basis of such teachings in almost all religions? First of all most of these religious teachings are of very ancient origin and were produced at the time when the humans lived in stone ages with hardly any technological achievements. Hence some felt that it was better to give humans the opium of better after-life so that they could be used as slaves for few masters without grudging or questioning. This could be one of the explanations.
The other explanation could be that as life was evolving in this planet earth there were visitations in spaceships by human-like forms from advanced civilizations of different planets and worlds. These could also be Gods of ancient times. These aliens came to colonize this virgin planet. As they settled they multiplied among themselves and may have even mated with the evolving humans on this planet. The purity of race might have become an important factor at that time and may have been the basis for racism of human race. The Indian caste system could also have been the result of this desire to keep the purity of race and hence the notion that we are one of the oldest civilizations of this planet earth maybe true. Though the aliens stayed on earth but to them the planet of origin or home must have been heaven and primitive life of earth as hell. This could have been the genesis of heaven in after life. Since they came from very advanced civilization it is quite possible that they must have made the conditions of life on their planet very sustainable and pleasant. I believe that as we expand our technological frontiers we will also make this earth a very hospitable and sustainable place to live in and then will colonize or visit other planets. We then might call earth a heaven in comparison to some other planet that we might visit, where life maybe in primitive state of development.
This desire of the aliens to go back to the parent planet might also have been the origin of preserving the dead bodies. Thus mummification in Egypt and burial of dead in other cultures was the mechanism to preserve the bodies till the arrival of spaceship from the parent planet so that the bodies could be resurrected and taken to it. However as the time passed this became a ritual handed down from one generation to other. The memory of the parent planet must have been strong in the genetic code of early humans, but as the time passes and our genetic material undergoes transformation we will slowly forget these customs and rituals and evolve ones which are based upon the realities of this world.
Energy-wise it becomes very difficult to get out of the gravity of this earth. Yogis have said that by willing one's own death, one can use the gravity of sun and moon to help the transmigration of soul to other worlds. For example Bhishma Pitamah in Mahabharata stayed on the prickly arrow cot for about six months before he left his body by will at winter solstice. Similarly Swami Vivekananda studied the almanac thoroughly before deciding when to leave his body. They obviously understood the effect of gravity on human thought and memory (soul). But that can be done by very few people. Most of the humans become residents of this planet earth both in bodily and ethereal forms. Probably in ancient times humans could do that because of the genetic make up of the aliens from advanced civilizations but as our genetic material gets mixed up with evolutionary life forms of this planet we might not be predisposed any more to those commanding heights. Shri Ramakrishna used to say that the Yoga of Kaliyuga is Bhakti because other Yogas like Raja Yoga etc. are difficult to practice and may require super human efforts. For ordinary people Bhakti Yoga is an easy way out. Maybe he understood intuitively the genetic process of evolving humans.
As the numbers of humans have increased on this planet earth, the web of love and human bond has become stronger. We should realize that this planet earth is our permanent home and is all that we have and this is both heaven and hell. We are all part of the web of love of this planet, and there is nowhere else to go. If we take this view then we will change our thinking so that we do everything in our power to make this planet a very pleasant place to live. We will then stop over exploiting it, killing our fellow humans and plundering the resources and make it possible for technological advancements for intergalactic space travel. We should therefore try to create sustainable and happy world for all our future generation because most of us will always be born again and again on this planet.