OK, Let`s all assume the Bible is correct, just for a second, the explanation is as follows.... Pre-flood era there was a unique atmospheric pressure with Oxygen enriched molecules combined with a suspended layer of a water above the ozone layer that filtered out radiation, UV ray, gamma rays etc, thus providing the perfect occurrences of photosynthesis, which ultimately is humans source of food, hence providing the maximum amount of life spans a biological entity is capable of producing. In this case pre-flood man was capable of living in excess of 900 year, the human anatomy shows that there are bone structures that keep growing until the day you die such as the orbiculares occuli , the bridge above your eyes. the nasal bones, and other facial structural components, portions of the ears, portions of the spinal chords etc etc. This is why age can be determine by examining a bone structure or skeletal remain, an 80 year old bone structure varies significantly of that of a 20 year old, so just imagine a bode structure of a 800 year old man, neanderthal is indeed man, just a very very old man.
Now before all you guys start with the name calling, your in fairytale land, stupid, moran, idiot, tooth fairy,Santa clause, lockness, blah, blah, blah....save it cause I have heard it a million times before and I am just answering his question from an alternative perspective of that of evolution, not here debating wether its true or not, beside if you don`t believe in it then why even bother asking a question that your not going to like the perspective answere.
here we go lol 
....................... ........
We are creatures of God, and God left (why? when will he return? how comes he only keeps in touch with a fraction of us?) us with a written guide, the bible, to dispose of ourselves and find hapiness if we follow his principles... our principles. If you do not follow these principles you ll find evil and suffering and will perpetuate them, as sure as following these principles will lead you to hapiness and will allow you to perpetuate it.
God intervenes in our lives at night when we sleep, especially in our dreams, but we have to read the bible , his holy writings, and pray, to stay wired to him and keep listening to, looking at, the signs he puts on our path. As people lose faith in him, they cannot communicate with him anymore, communications are troubled. The more we re harmed, hurt, the more we harm, hurt, the more we re disconnecting ourselves with him and what makes us feel really good and happy. Those who lose contact with him, who refuse progressively to understand they re only his creations and cannot BE Him, they become more and more prone to fall for Evil. Is evil another God fighting the good God? Attempting to be, become God himself when we re only designed to be his creation, is a sin. We cannot be anything else but his creatures and follow the mechanics he created, just as a kid can only do and say what his father, parents, told him to do and say.
Hapiness is linked to faith. Faith is found following the guide left by our creator. We are not supposed to understand more, arent designed to understand more. We CANNOT UNDERSTAND MORE THAN WHAT WE RE LEFT WITH BY THOSE WHO CREATED US. Any attempt to do so leads to madness and death. Which means genuine hapiness can only and solely be found in faith, family and unconditionnal love, submission and respect for our creator. Just like loving and respecting our Father insure our best odds of survival and hapiness, if our father is a good father, following himself the principles of His creator.
Good things lead to good things, this is mathematical and scientifically proven. Does a good life following the principles of God leads to a good afterlife?
What is the afterlife, another dimension, another earth, another parallel universe where we reap what we sow ? Is the afterlife... Becoming God himself?
Why all of this? Good fucking question. But there are some patterns we re all able to see and cannot deny. And mankind is going in a direction. Everyone knows it. Something is coming. Also how comes the more we try to understand, the more we discover, the more things seem complicated and complex? It's like everytime humans understand and discover something new, something new and impossible to understand is created simultaneously. Like if someone, something was creating new boundaries everytime we reach the old ones with no end in sight. Do you guys really think there's is something to be found in space ? The more we learn about space, the more we figure we should take care of earth, because space is absolutely not designed to sustain our survival.
Are the theories of natural selection, evolution, of the subconscious, just ways to explain the "mysterious and unpenetrable ways of God" , but always, "mysteriously", fail to do so?
Are we characters of a virtual world, some kind of video game, programmed by developpers, can we do something different than what has been written in the code, the scenario, is the background, are grass, sky, sun, ilusions as they are in a video game? Can we be, become something else than the character we ve been designed to be, to become?
If we ve been created by developpers... Who/what created them, and why? And who created those who created them, and why? And so on...
