Lord, make me to know my end and what is the extent of my days; Let me know how transient I am. (Psalm 39:4)
Quoting from the book entitled "What Happens After Life?" by Ron Rhodes; "Life on earth is short. Life in heaven is long. (It is eternal). It therefore makes good sense for Christians to take a little time to ponder timeless truths about heaven and the afterlife. Put another way, we Christians are wise to live our short lives on earth in view of our imminent transition to our long lives in heaven."
A three month old son of some friends suddenly and unexpectedly died. From a limited human perspective, some might say that this baby died prematurely. But we know that that there are no premature deaths in God's sovereign timetable; Your eyes have seen my unformed substance; And in Your book were all written the days that were determined for me, when as yet there was not one of them. (Psalm 139:16)
If you die at only three months of age or you are a 100 years old, life on earth is short compared to eternity that follows. There are no promised days for any of us. For us Christians, it is comforting to know that our sovereign God alone determines our number of days on earth. Each day is a gift from God and should be lived in light of eternity, fully trusting and obeying Him.
Each of us will someday suddenly and unexpectedly also enter into either eternal life in heaven or eternal death in hell; And inasmuch as it is appointed for men to die once and after this comes judgment, so Christ also, having been offered once to bear the sins of many, will appear a second time for salvation without reference to sin, to those who eagerly await Him. (Hebrews 9:27-28)