श्रीमद् भगवद्गीता

Death is not the end, dear seeker, but merely a change of garments for the eternal soul.

Krishna reveals this profound truth to Arjuna in the second chapter:

न जायते म्रियते वा कदाचिन्नायं भूत्वा भविता वा न भूयः।
अजो नित्यः शाश्वतोऽयं पुराणो न हन्यते हन्यमाने शरीरे॥ (2.20)

The soul is never born, nor does it ever die. Having come into being once, it never ceases to be. It is unborn, eternal, ever-existing, undying and primeval. It is not slain when the body is slain.

Krishna further explains with the beautiful metaphor of changing clothes:

वासांसि जीर्णानि यथा विहाय नवानि गृह्णाति नरोऽपराणि।
तथा शरीराणि विहाय जीर्णान्यन्यानि संयाति नवानि देही॥ (2.22)

Just as a person casts off worn-out garments and puts on new ones, so does the embodied soul cast off worn-out bodies and enter into new ones.

But what determines where the soul goes? Krishna teaches in the eighth chapter:

यं यं वापि स्मरन्भावं त्यजत्यन्ते कलेवरम्।
तं तमेवैति कौन्तेय सदा तद्भावभावितः॥ (8.6)

Whatever state of being one remembers when leaving the body, that state one attains, being always absorbed in that thought.

The consciousness cultivated throughout life shapes the soul's journey after death. This is why Krishna emphasizes remembering the Divine at the time of departure and throughout life itself.