The time of our death is unknown

We may spend our lives running from death and denying death, but that won't stop death from coming at its appointed time.

There is no man who has power and authority over the wind to restrain the wind,
Nor does he have authority over the day of death;
There is no discharge [from service] during time of war,
And evil will not rescue those who [actively seek to] practice it. Ecclesiastes 8:8

Scripture states that eternal realities should influence the character of our present life, right down to every word we speak and every action we take.

In those rare times when we do seriously consider the afterlife, it seems strange, dreamlike, so other-worldly as to be unreal. So we come back to “reality”—our present lives and plans and possessions that we can see and hear and touch and feel and taste. Things are real. Now is real. So we return quickly to the pressing business of the day, that which is immediately relevant, those all-important matters of the present. These might include what’s happening in Hollywood or on Wall Street or in Washington or London, or the NFL or NBA; or what new self-help technique can make us beautiful or happy, or how we can decorate our house, or what kind of car we want to buy or where we can get a low-interest loan. We live as if these shadowlands were the real world, the ultimate reality.  But Scripture tells us they are not. - Randy Alcorn

What does God have to say about our lives here? He say that this life is brief.

[a]Yet you do not know [the least thing] [b]about what may happen in your life tomorrow. [What is secure in your life?] You are merely a vapor [like a puff of smoke or a wisp of steam from a cooking pot] that is visible for a little while and then vanishes [into thin air]. - James 4:14

 David likewise sought to gain God's perspective in light of the brevity of life --

“Lord, let me know my [life’s] endAnd [to appreciate] the extent of my days;Let me know how frail I am [how transient is my stay here]. 
“Behold, You have made my days as [short as] hand widths,And my lifetime is as nothing in Your sight.Surely every man at his best is a mere breath [a wisp of smoke, a vapor that vanishes]            Selah. 
“Surely every man walks around like a shadow [in a charade];Surely they make an uproar for nothing;Each one builds up riches, not knowing who will receive them. 
“And now, Lord, for what do I expectantly wait?My hope [my confident expectation] is in You.  Psalm 39:4-7

Is The Time Of Your Death Predestined By God?