Why Do We Die?
We die, not because God has decided it is our "time," but rather, it is because we inherited sin from our original parents, Adam and Eve.
In the book of Genesis, it relates how God made the first human couple, Adam and Eve, and placed them in a paradise home. There were many beautiful trees, an abundance of animal life, and plenty of food for them to eat; they were truly blessed. However, God told them that if they wanted to continue with these blessings, it required for them to remain obedient; yes, God laid this commandment for them to follow about a particular tree: "You must not eat from it, for in the day you eat from it you will positively die." (Genesis 2:17) Hence, Adam and Eve recognized that death was only possible if they chose to disobey their loving Creator. What choice did they make?
Sadly, Adam and his wife, Eve, deliberately disobeyed God's instructions. Thus, when God was announcing the consequences of their sin, He said: "Dust you are and to dust you will return." (Genesis 3:19) Due to them becoming imperfect, their imperfection, or sinfulness, would eventually lead them to death.
This sinful condition of Adam and Eve was also passed on to their offspring, which includes us and all humans. Think of it as a hereditary disease. Adam had lost the opportunity to live forever, and not only that, but transmitted imperfection to his offspring. Thus, the Bible states: "That is why, just as through one man sin entered into the world and death through sin, and thus death spread to all men because they had all sinned." (Romans 5:12) Indeed, the consequence of sin is death, and since we all inherit sin, we all die as a result.
You might ask: "So now what? Are we doomed to die because of sin forever?" Not at all! God provided a remedy for this problem. The Bible says: "The wages sin pays is death, but the gift God gives is everlasting life by Christ Jesus our Lord." (Romans 6:23) I'm sure many of you know the important role Jesus plays in eliminating sin and death. Jesus explained that he came to earth: "to give his soul a ransom in exchange for many." (Matthew 20:28) Yes, Jesus would give up, or sacrifice, his perfect human life on our behalf. It was God who provided the ransom by sending Jesus to the earth: "God loved the world so much that he gave his only-begotten Son, in order that everyone exercising faith in him might . . . have everlasting life." (John 3:16) What a wonderful showing of love from God and his Son, Jesus!
Hope For the Future
Is there hope for those who have died? There is. Do you know of a man named Lazarus in the Bible? He was a friend of Jesus who had died from an illness. Regarding him, Jesus said: "Lazarus our friend has gone to rest, but I am journeying there to awaken him from sleep." (John 11:11) And so Jesus traveled to the memorial tomb of Lazarus; he had been buried in a cave. Shortly after arriving, Jesus cried out with a loud voice: "Lazarus, come on out!" The result? "The [man] that had been dead came out." (John 11:43, 44) Even though Lazarus had been "sleeping" in death for four days, Jesus restored him back to life.
Likewise, Jesus said: "The hour is coming in which all those in the memorial tombs will hear his [Jesus'] voice and come out." (John 5:28) Yes, a time is coming in which many of those who have died will be restored back to life, and like Lazarus, they will be resurrected to live here on the earth. (Psalms 37:11)
Though, you may wonder: Will these dead ones be resurrected back to life only to grow old and die again, somewhat like Lazarus? No, the Bible shows that there is a time coming where "death will be no more," and so no one will be growing old and then dying. (Revelation 21:4)