We believe when we die we take on another body but a spiritual not material body in another world.
I believe when the Gita says we return it means to a condition not the physical earth as it is a spiritual book describing the soul and the fall and rise of spiritual,progress.
The only thing we believe dies return are the qualities not the individuality of the person. So the flowers of last spring return again this year but by that we do not mean the exact same flowers return but the qualities such as the colour, shape and fragrance return.
So I see today the return of past generations who deny the Manifestation of God. Not the same individuals but the same kind of people..
A return is indeed referred to in the Holy Scriptures, but by this is meant the return of the qualities, conditions, effects, perfections, and inner realities of the lights which recur in every dispensation. The reference is not to specific, individual souls and identities.
It may be said, for instance, that this lamplight is last night’s come back again, or that last year’s rose hath returned to the garden this year. Here the reference is not to the individual reality, the fixed identity, the specialized being of that other rose, rather doth it mean that the qualities, the distinctive characteristics of that other light, that other flower, are present now, in these. Those perfections, that is, those graces and gifts of a former springtime are back again this year. We say, for example, that this fruit is the same as last year’s; but we are thinking only of the delicacy, bloom and freshness, and the sweet taste of it; for it is obvious that that impregnable centre of reality, that specific identity, can never return.