It is not so difficult to logically understand life of eternity from our own mortal constitution. As we know that we – humans, as mortal physical creatures, do not have the built-in-design to live forever. Our genetic code is programmed to physically deteriorate our material-bodies, slowly and consistently through the process of aging, which ultimately leads to ceasing of our material-existence at a specific moment of time – called death.
The entire system is designed and orchestrated in such a manner that in a ball like planet called Earth, multitudes of humans take birth, grow-up, die-off and decompose into physical matter to be reused in the making of others who are to continually come and replace the previous ones. If one could imagine in time-lapse, it’s like assembling and dismantling of humans from the same physical-matter that could be part of another human in the past, in a manner similar to recycling of constituents.
All of this is so meticulously cycled by the Creator (The God) that the rate of birth and death do not out-beat each other to threaten the survival of humans itself. The entire mechanism of reproduction, stems from temporality of life, and would not have been required at-all, if the human existence was designed for permanence. However, at the same The God – The Creator has informed us that He created us for a life or permanence to come in the hereafter, and He embedded the urge for it in the constitution of the human being. He also kept sending revelation to inform us about this from the time He created the first human.
The nature of Heaven and Hell is permanent or eternal, against the temporal nature of the present world, wherein nothing is permanent – it had a beginning and will have an end. The God says in the Qur’an: “Verily the God-fearing shall be in a secure place.” [Qur’an: 44:51]. A place, which is safe from every kind of fear, grief, worry and danger, hardship and trouble. According to a Hadith, the Prophet ﷺ said: “It will be proclaimed to the dwellers of Paradise: Verily, there is in store for you everlasting health and that you should never fall ill and that you live forever and do not die at all. And that you would remain young and never grow old. And that you would always live in affluent circumstances and never become destitute, as words of Allah, the Exalted and Glorious, are: “And it would be announced to them: This is the Paradise, which you are made to inherit as a reward for your deeds.” [Qur’an: 07:43] (Ref: http://sunnah.com/muslim/53/26).
The God further says in the Qur’an: Those who reject Our signs and turn away from them in arrogance – the doors of Heaven will not be opened for them, nor will they enter Paradise, until the camel passes through the eye of the needle. Thus, do We reward the guilty. For them is a couch of hell, and above them are sheets of fire. Thus, do We reward the wrongdoers. As for those who believe and do good – We never burden any soul beyond its capacity – these are the inhabitants of the Paradise; abiding therein eternally. We will remove whatever rancor is in their hearts. Rivers will flow beneath them. And they will say, “Praise be to The God, who has guided us to this. Had The God not guided us, we would never be guided. The messengers of our Lord did come with the truth.” And it will be proclaimed to them, “This is the Paradise, which you are made to inherit as a reward for your deeds.” [Qur’an: 07:40-43]