The Helpless situation of that Day : God informs: 80: 33-42.
Here the picture is painted by God about the people running away to save their own lives on the Day of Judgment followed by the condition of those people who believed Allah and Obeyed Him and His Prophets, living the life as per His Commands- will be in happiness when they are raised up for Judgment (Resurrection). The Disbelievers will be in utmost difficulty and gloomy condition without any hope nor any helper.
Now let us note down the following points: Death leads one to the Eternal world (so death can be considered as the Gateway to the Next World of permanent life). "The Grave" may be understood to be the period between physical death and immortal life, whatever may be the mode of disposal of the dead body. Whatever we say and think about the Truth of God, does not affect His system. If we say that there are creatures on the Mars, then they won't appear over there, just because we have said so and if God has created none over there! If we sa