Science says, every 3 year, every cell of our body is changed.
The cells in body continue to die and are remade.
GITA says similar thing, from birth to death we continue to change our physical body.
We give up our childhood-body, when we become adult.
We give up our adult-body when we become aged.
When the body is too old to work, we die and change into a new body by way of a new birth.
The "Life inside us" is in a continuation.
It is a form of Energy.
According to science, nothing is destroyed.
Things just transform into other shapes.
For example, ice can become water and water can become steam and steam can become water etc.
Variations in heats transforms physical shapes of being.
Point as said inspired form GITA :-
The life inside us was here before our birth.
It is here in us when we are passing through this body.
It will remain here even after our death,
and and will find itself a new body after our death.
Haresh Raichura
25/10/2014