Jai Sri Ganesha,
The future exist on the foundation of past, and present experience that truth with hidden karmic baggage,
The belief of man's future existence means it about his past reality, midst of the two, present exist in its transit reality to repay or equate the barter truth,
Existence in eternity is not a strange phenomena, each individual resort to for a while or for a long to address its earlier existence in truth wizard,
Law of Karma is a chain on the pitch of time that repeat itself but in different scenario and different reality to check the karmic baggage,
Jai Mahadev