Genesis 2:7 shows us this formula: Dust(Body) + Breath Of Life(Spirit) = Soul(Living Being). This is Life.
Eccle 12:7 shows us this formula: Dust(Body) - Breath Of Life(Spirit) = Death(Absence Of Life). < You no longer exist.
Your Spirit returns to God who gave it. Your body returns to the dust, where it was from. The soul no longer exist, for to make a soul exist, you need a combination of body and breath.