Why does no afterlife sound so scary and sad?

Because we have something to hope for. Paradise for mankind was on earth. God has clearly designated the earth as the permanent home for humans. The Bible says that God made our planet to last forever. (Psalm 104:5) It also states: “To Jehovah the heavens belong, but the earth he has given to the sons of men.”—Psalm 115:16.

The Bible teaches that “the righteous” will live in Paradise. But who is righteous in God’s eyes? Not the person who engages in the rituals of his religion while ignoring God’s will. The Bible says: “Does Jehovah have as much delight in burnt offerings and sacrifices as in obeying the voice of Jehovah? Look! To obey is better than a sacrifice.” (1 Samuel 15:22) Simply put, “the righteous” who will live forever in Paradise are the ones who obey God’s commands as outlined in the Bible.

http://www.jw.org/en/publications/magazines/g201301/what-is-paradise/#?insight[search_id]=b65be791-1512-4118-b809-dc234aa30a46&insight[search_result_index]=6

I don't know. To me, the afterlife just seems like fantasy and wishful thinking. We have life...which is honestly pretty amazing... But as a species we often commit and/or tolerate some pretty awful things, like war, because...well...Those people who die are in a better place. No. They're just dead. We are so lucky to even have life at all. The only greater tragedy is that we want a perfect life to come after, despite having failed to live an authentic life here and now.

If you in the true path in this life, no need to be afraid in the afterlife. :)

i don´t know, but more and more people become aware that there is a spirit world

Fear of death is a natural instinct. The notion of an "afterlife" has been sold as a manner by-which we can "beat" the inevitable result of life - death.

Once we have bought into the notion of an "afterlife" at some level, stepping back from that notion can be depressing for a time.

Because you do not know what is on that side of existence. But I have been there a few times by way of N.D.E.'s and I know it is extremely FAR more exciting on that side than on this side. That side makes this side look like Bear skins and stone knives.

It is scary and Sad to those that were told "IF they had been kept dead, they would have gone to Hell! This changes Atheists and Devil followers to come to GOD! With GOD is LOVE!
Watch "The Lazarus Phenomenon" and "The Search For Heaven" FREE over this Internet!

Maybe because you're not emotionally mature enough to accept reality.

Perhaps because you do not have a proper understanding of it. The afterlife is not as it it commonly taught ... the good in heaven or the bad in hell. When we die we simply go to the grave. That's the real, scriptural definition of hell.

That, however, doesn't mean that there is NO afterlife. Quote the opposite, in the near future those who have died will be restored to life on a paradise earth, with a chance to live forever.

John 5:28,29.
Revelation 21:3,4

It's because the very idea of annihilation is utterly depressing; it would show that our tiny little lives are futile and meaningless and purposeless and that there is no intention to life. Just finding ourselves here for a blip, to try to enjoy the fabulous wonders of living on this gorgeous planet, is the best we can strive for. But what is the point of seeking to understand the intricacies of life in its myriad forms if we cannot do anything with that knowledge other than seek to make our lives more comfortable and interesting? We might as well just indulge in our every whim, regardless of anything or anybody else, for tomorrow we could be dead.

Yet something deep within us screams out in protest; we want to keep on living! We don't want to be conquered by death and oblivion! We're worth more than that, we matter more than that, surely? Yes, is the answer. We were designed and created for life, and we were entrusted to look after this planet bursting at the seams with life. That is why God, our Creator, "he set eternity in the hearts of men" - Ecclesiastes 3:11. That is where our yearning comes from!

Even when undergoing horrific suffering, people have known there will be release and something far better; Job spoke of his Redeemer living and that he would stand upon the earth, "And after my skin has been destroyed, yet in my flesh I will see God... with my own eyes." Job 19:25-27 This is a very ancient piece of literature. He did not know much about any afterlife, but his faith in God was enough to know that God would deliver him.

Thousands of years later, Jesus came from Heaven to bring us back to God, and full understanding came. He stated that He is the resurrection and the life, and that all who trust in Him as the Redeemer will live in glory. He also explained that He came to destroy the power of the Devil, who holds the power of death. Jesus has set "free those who all their lives were held in slavery by their fear of death." (Hebrews 2:14)

It is not the Christian religion that has instilled fear of death into humanity. It is the Devil. Jesus has conquered him, and sin and death. Those who learn just who Jesus is and what He did have no fear of dying! They rejoice at the prospect of eternal life in glory, all because of what Jesus has done to deliver us from our sin, which leads to death. The grave is just a stepping stone into glory, for those who trust in the deliverance Jesus gives.

Because "God put eternity in their hearts."

for a dying Atheist that's the best possible scenario if it were true