It is a matter of identification. If "I" am the body then I die, but if "I" am identified with the what you call life force and I choose to call by what ever name I wish, then the body died and I did not.
The 'life force', or soul, or Brahman is always alive never dies. Just as space never disappears(except may be in a black hole), but can be contained in a pot. So when pot is broken the pot space just merges back in the general space pool.
Bhagavat Gita Sloka 2.23 says:
Text 23
nainam chindanti shastrani
nainam dahati pavakah
na cainam kledayanty apo
na sosayati marutah
Translation
The soul can never be cut to pieces by any weapon, nor burned by fire, nor moistened by water, nor withered by the wind.
Vedanta says, ‘You are chaitanya’, Chaitanya means, awareness or consciousness. I am aware of my body, the mind, the intellect. I am basically awareness through which everything is seen, everything is objectified, known and perceived. Therefore ‘aham’ which means ‘I’ is pure consciousness, pure awareness or chaitanya.