This question can only be answered by the theological writings of Emanuel Swedenborg.
Swedenborg discovered through profound visionary insights that the kingdom of heaven was arranged like the organs of a human body—called the “Grand Human.” This is because God’s Love and Wisdom represents infinite humanness and therefore (according to divine order) must flow into and maintain similar forms (called “correspondence”).
These God-created forms, when looked at from their true essential functions, represent a perfectly unified organic theater of reciprocal support and cooperation. The varied functions found within human bio-structure are physical metaphors of spiritual love and heavenly activity. That is why angels—and the quality of their hearts—are arranged into heavenly communities that mirror the living cooperation and reciprocal functions of human organic design (increased unity through a diversity of reciprocal love).
When the flow of God’s Holy influence becomes disharmonized because of some lack of growth and response in one of these heavenly communities, Swedenborg claimed that “there shall be straightway summoned from some earth those who will make up the deficiency, in order that the proportion may be maintained, and that in this way heaven may stand firm.” (AC 6807)
While the Lord God has many individuals from many planets throughout the great universe to choose from, good people from our own planet are regularly taken to make up this deficiency. (The reason why this process happens to so many young children is when heaven is in need of additional innocence to maintain cosmic harmony.)
In other words, the needs of heaven (and maintaining the causal integrity of correspondence between God and created beings) trump our individual and personal needs to enjoy the continued physical presence of our loved ones and friends.
One must elevate one’s mind and look at the big picture to rise above the emptiness one feels when a loved one is taken away. This is difficult because we cannot observe the spiritual world, which is the most important part of our universe. However, we should not act as though something unfortunate has happened to our lost loved ones. Those who leave us early come into a realm where they are more alive than ever and simply do not identify with our sorrow.
TheGodGuy 
“Those who leave us early come into a realm where they are more alive than ever and simply do not identify with our sorrow.”
What does early mean? Before our Biblically allotted time span of 70 years? 50 years? 30 years? How do we know they are summoned to heaven? There may be wicked twenty year olds and thirty-year olds.
But in general, I agree with this observation since I think most people are heaven-bound (Shhh! We do not want anyone to hear, especially the younger generation! They might get lazy and complacent if they knew this! Let them fear for their salvation – that will keep them on their toes.).
Roger
Roger,
I do not think many teenagers read this blog. As far as age goes it doesn’t matter. We tend to think good people are taken from the earth too soon and that they should ideally live the longest. The point is that people can die unexpectedly to meet certain needs in the spiritual world – regardless of how strongly we feel they are still needed here on earth, with us. From earth we can never know for sure why anyone dies. I am merely sharing an observation made by Swedenborg, and, that we have to think beyond terrestrial concerns.
Spiritually yours,
TheGodGuy