Firstly I need to clarify the question, my the meaning of life do we mean all life, or the life of a human?
In fact the second definition would fit inside the first so I shall start there, obviously there are hundreds of theories, its one of the most asked questions of all time, and of course there is no one answer. So I will just give my own oppinnion. A theory that I like to call the awakening of the Universe, which I have adapted from an idea that I fisrt descovered while reading the book "Maya" by Jostein Gaarder. (Fantastic novelist! This book and another called Sophies world streach the mind fantasticly and are great reading for anyone with an interest in Philosophy)
The idea looks at evolution and asks if the pattern is random or if it is evolution is leading to something. After all we have evolved to be the way we are because it is the most usefull for our survival, 2 arms, 2 legs, a large brain all essential to those most evolved species on the planet (there are exeptions like sea creatures but theyre world is a completly different one to ours so I shall stick to land dwellers) if this is the case that means if we could restart time it would happen exactly the same, (as least evolutionly speaking.) But if this is the case is nature ambling on randomly to no destination, or does it have a predetermined goal? well its my veiw that it does.
At the beggining of life (I am taking about evolution here so I hope I dont offend any Christians in this, if I do its not my intention) there was only very small, one celled organisms, from there as you know things evolved and grew into larger and more complex creatures, not only this but they formed a web by which they, sometimes intentionally and sometimes unintentionally helped each other to survive, through food chains etc. Though weaker species became extinct life grew and grew untill eventually vitually all areas of the world were populated. If we look at any know species each has its own role that helps life as a whole to survive, (even viruses keep populations under control, and flys help decomposition ) This brings me to my second life definition, the meaning of human life.
Human life seems to upset this rule, we seem not to have any role at all but I belive that we must have, (the most evolved species not having a purpose when everything else does seems a little silly to me) But exactly where do we fit in to the grand scheme of things. Its my personal veiw that being the most complex species in more than one way, it would make sense for us to have a more complicated purpose. Lets go back to what I was saying about species evolving, we started off with life being one celled, now creatures are alive that have millions of cells. The purpose of a cell in these creatures is to serve one part of the whole.
Much like every creature does to the planet. What if we are just a part of the life of the planet, could life on earth not be attributed to one huge singular species, with all the animals plants and people acting like cells? (Seems a bit strange, but just let your mind open to the idea and it does make sense) So a humans role would be the brain, we are the part that names everything else, that asks the questions and our collective thinking could therefore make up the thoughts in the planets head, (much like in our brains when we try to work something out, lots of ideas circulate and our the one that seems to feel the strongest possibility provails over the others). So we could argue that the meaning of life is to evolve into a huge planet sized entity.
Or we could if you will bare with me take it one step further and say that our planet is not an animal at all, but a tiny cell in the make up of the whole universe, it could even be the only living cell in the universe, and of that cell we as humans are the nucleus. Going back to secondary school biology I belive im right in saying that it is this part of a cell that splits first when making a new cell. Are we not getting close in technology to populating new planets? This could be related to that process, first we split and then take with us other aspects of life (such as plants) that will make up the life that will eventually take root on a once lifeless planet. Over a billion, billion ages of time with some planets dying and others surviving and creating new communities with other planets which in the definition of my theory would mean new greater lifeforms, the universe will eventually awaken as one perfect being.
Does this theory fit in with God? I think so. It could be that we are all a part of God, (he even says he is in all of us in the Bible, mabey thats what he meant) or mabey Gods reason for creating life could even be as simple as being lonely, as im sure it must be being the only entity of his thinking capacity, mabey he made the Universe because he wanted a friend to talk to, someone to discuss philosophy with just like am with you now. There are many other reasons, and the ones I have mentioned are more than likely wrong, but it gives you an idea.
There are im sure a thousand loop holes in my theory, (there always are, thats why no one knows the exact answer to the question of this thread) and I realise this veiw is both mind boggling and seems almost totally ridiculous but my view is that the universe is both mind boggling and also a little riddiculous, so it fits well in my eyes.
I hope I did the theory Justice and that it makes as much sense as possible, I'm deffinatly not going to say this is how it would work in practice.
Its not my only theory on the meaning of life, another is that life is just a lesson that God is teaching us on our way to the afterlife. Personally I like to think of it as a little of both.
At the end of the day "Wisest is he who knows that he does not know" please someone tell me whos quote this is so I can give the man credit for it. (Wish I had not lent my copy of sophies world to a friend, or i could find out for my self)
Untill next time God bless and keep questioning.