We have a biological imperative to be safe, whole and injury-free.
All stimuli is evaluated through the filter of past experience against this imperative.
We have a similar mental imperative.
Our biological imperative is known as the Survival Instinct, the mental equivalent is our Identity.
Any change, or disruption, in our sense of who we are – our multi-layered and -faceted Identity – is seen as a threat and outgrowth of our Fear of (physical) Death.
To the extent that we accept the fact that we will die and that it could happen at any time, we can be free and live peaceful and powerful lives. (By seeing each moment as precious and rare and thus making the most of the time we have and being truly present to the miracle of each moment.)
To the extent that we deeply, truly know that we are not who/what we think we are, we can be free and live peaceful and powerful lives. (By realizing that, deep down, at our core, we are perfect spiritual beings – we need only improve our behavior to bring ourselves back to our true nature.)
To the extent that we resist the eventuality of death or over-identify with our Identity, we will live small lives constrained by fears, rules, judgments and limits.