Genesis 3:22-24 - God deliberately separates Adam and Eve from the tree of life. He knows that it is THE SOURCE of their immortality. If they eat of it, even in their sinful states, they would "live forever".

So, Adam and Eve were not naturally immortal even before the fall. How then could they be improved after sin?

Matthew 27:50 - Jesus "breathed His last" or "gave up the ghost"…

Luke 23:46 - Again, death, "breathes His last", "surrendered His spirit", etc. are all synonyms and are translated interchangeably.

Psalm 104:29-30 - God sends forth His SPIRIT, and we are created. He takes away our BREATH and we die. Again, these words are both translated from ruach.

Job 33:4 - God's SPIRIT has made us… And His BREATH gives us life.

Job 34:14-15 - Again, note the equivalence of BREATH and SPIRIT.

Isaiah 42:5 - God gives BREATH and SPIRIT to people (this is just reiteration of the same thing as they are the same word ruach.)

Job 27:3 - When we breathe, the Spirit of God is in our nostrils.

Genesis 1:21 & 24 - God creates great whales and every living creature [nephesh chayyah]

James 2:26 - The body that doesn't posses a SPIRIT [BREATH] is dead.

Ecclesiastes 12:7 - When we die, we become dust. The breath of life (our spirit) returns to the God who gave it.

To conclude this study of "SPIRIT" and "SOUL", lets discuss them as if they were mathematical equations. (Based on Genesis 2:7 and Ecclesiastes 12:7)