A cynical said that, by far, the first cause of death is Life since Life has, by definition, an100% mortality rate in which unexpected events such as accidents+ illnesses+ war+ disasters represent only a very, very tiny proportion.
#1 So:
Maybe finding the secret of Life is to die** before death in order to realize that there is, in fact, no death per se since no one can die twice.
#2 Then:
If there is no death, then life is eternal.
#3 But:
If Life is eternal, how can one find its secret by dying?