Fear of death.

Many people have a fear of death. Working as I do with the elderly and others in community health, it's not uncommon for people to express fear and agitation in relation to what we know must happen eventually to each of us - barring the rapture happening. (The rapture is the an event mentioned in the Bible where all the Christians alive on earth will be taken up into heaven. Opinions differ as to when the rapture will occur in relation to the great tribulation which will destroy the earth as we know it.) From what I have heard from anecdotal reporting within the health system, people who exhibit a fear of death before it is their time are often very calm and peaceful when it happens. We do not know the workings of God in the last days, hours and minutes of a person's life.

Death was not part of God's original plan for humanity. God warned Adam and Eve not to eat of the tree of knowledge of good and evil, or they would die. When Satan tempted Adam and Eve he told them that they would not die, rather they would be like gods. Satan's purpose is always to lie and deceive and ultimately destroy.
With Adam and Eve's original sin, death entered the world and all living things eventually die. Even inanimate objects such as rocks and buildings crumble and decay. The Bible tells us that the wages, or what we receive for sin, is death. As we are all sinners we know that we deserve it.
The good news of the gospel is that Christ, by becoming human, chose to die in our place. It is only because of  His death on the cross that we who have committed our lives to Christ have the promise of eternal life. Our physical bodies here on earth will die, but we will have a new body and a new life with Christ in heaven.
The Bible provides some verses in which may comfort those afraid of death:

^" Since the children have flesh and blood, He [Jesus] too shared in their humanity so that by His death He might break the power of him who holds the power of death—that is, the devil—  and free those who all their lives were held in slavery by their fear of death.  For surely it is not angels He helps, but Abraham’s descendants."  (Hebrews 2:14-16)

"For while we are in this tent, we groan and are burdened, because we do not wish to be unclothed but to be clothed instead with our heavenly dwelling, so that what is mortal may be swallowed up by life." 2 Corinthians 5:4

"For this perishable must put on the imperishable, and this mortal must put on immortality. But when this perishable will have put on the imperishable, and this mortal will have put on immortality, then will come about the saying that is written, "DEATH IS SWALLOWED UP in victory. O DEATH, WHERE IS YOUR VICTORY? O DEATH, WHERE IS YOUR STING?" (1 Corinthians 15:53-55)

"The Spirit gives life; the flesh counts for nothing. The words I have spoken to you--they are full of the Spirit and life." John 6:63

A baby in the womb doesn't know what life will hold. He or she has some limited inkling of this life through what he can hear and sense in the womb. When the child is born, hopefully there will be people waiting who love and want this child, who will welcome the baby with loving arms and gentle words. We have every reason to believe that our Heavenly Father who loves us far more than any earthly parent, will be waiting to welcome us into a Heaven more wonderful than we can ever imagine here on earth. 
Jesus said:

"Do not let your heart be troubled; believe in God, believe also in Me. "In My Father's house are many dwelling places; if it were not so, I would have told you; for I go to prepare a place for you. "If I go and prepare a place for you, I will come again and receive you to Myself, that where I am, there you may be also.…(John 14:1-3)

In addition, there are some wonderful testimonies available of Christians who have experienced near-death incidents. These encourage us to be assured of the reality of heaven. I would recommend the testimony of Ian McCormack, an atheist who became a Christian following his near death experience. See https://www.youtube.com/watch?v=sTU7MfOgDKM
also Don Piper "90 Minutes in Heaven" - book and Youtube testimonies.