Existence is the perceptually self-evident fact at the base of all other knowledge,
i.e., that “existence exists.” [An axiomatic concept as such.]
To be is to be something, existence is identity.
To be is to be an entity of a specific nature made of specific attribute.

Some say the big “Why” question is the most beautiful question in life, that is, studying the mysteries, and that the answer, when it comes, is mind blowing or at least fascinating compared to “not knowing”. Is there Ground Being? An ultimate essence? Is this muddle of chaos that is our life on planet earth done on purpose? Is it a closed universe? Curved? Open? Infinite in all directions? What or who created the Big Bang? Are there multiple universes? Having definitive answers to these main ontological questions moves you like a force onto itself. It is uplifting and individualizing as all mystical experiences are. Answering the big “Why” moves you into the religious or certainty arena of belief.
Though some philosophers, theologians, and the intelligentsia, complicate simple facts, while holding on to the mystical allure; somewhere in all this confusion, is a single solution in the straight-forward manner to the big queries of life. A reality exists outside of the complex sapiens’ intellect, a brain which runs a fantastic simulation machine of life and we have to do everything we can to try and ascertain the really-real, to be objective and to find truth with reason and science. We must hunt down, one by one, the brain’s illusions and biases: the Nurture Assumption, the availability bias, the comfort gene, the prejudice of discovering patterns where none exist or ignoring patterns when they do exist because they are the ones we hate to perceive or ones to which we are subjectively adverse, the negativity bias and many other chauvinisms of our convoluted, painstakingly-slow  escape from our time as unaware DNA replicators.
Fundamental principles are a treacherous razor blade with this one cutting divide: going ahead with certainty or muddling along with doubt; certainty is theology; doubt is philosophy. Certainty closes down an open-ended inquiry for a theological theory of how, why and what the hell happened to bring this rather bizarre result. If I say there is no chair when I am sitting in one, I understand that the chair I sit in is there, but not in the “micro-cosmological sense”. If I say there is no certainty, when clearly there is much tentative knowledge of the world outside of our minds which we can all agree on, then I don’t mean that the chair and god are equivalent perceptual problems. Progress for man is measured slowly over the years. But is there indeed progress? To this day, despite having the freedom, much of humankind still embraces theology over philosophy. If I say to you that, “The chair is really there”,  you might say, “I am naive”. If I say, “There is no god because I don’t perceive Him like I perceive the chair”, you might say, “Believing is perceiving, and before you perceive, you have to believe”.
Science is a grudging latecomer to this debate. Yet now it weighs in: it says, reason, science and skepticism has the last word. If we say, “The modern theory of evolution produce the scientific atheists”, then one might counter, “And what of all those atheists since Democritus?” Now science says, “Man isn’t free! Life is chaos! There is no intention!” Right now I am writing about metaphysical purposes. Humankind can’t invent god and call him real. That was the easy way to find our purpose. Now we must find it in the void of space and the chaos of the universe. For most people, self-purpose in life is the most difficult thing about it. Better to be on a beach drinking. Better to find the god delusion. Willpower is gifted to you by the all seeing Judge. Better to hang yourself in the garage. If you are relieved of the responsibility for creating or the discovery of it, phew! You’ve just won a self-administrated lottery. Get the answer at the local bar, lecture hall, church, stadium, temple or mosque. You don’t have to live with doubt. 
It’s a Hell of a Deal!
Some fool is going to answer the big “Why” for you. He’ll explain the program and how it works, whether it is political science or theology, a near match I might add. The price? Your freedom, money and dignity, but after all, this is a great weight taken off your shoulders. Now the constant doubt is removed by scientific or theological allegorical neurosurgery. There are of course still the big “What” questions, but those can be found in an amalgamation of the alleged “good books” and modern scientific cognition itself. Once the “Why” has hogtied the “Hows”, it quickly moves to that rude lament: “Whatever!”
So you sign up and become sanguine about your future. Canines like me are always barking and  biting  at your heels but you’re not flummoxed at all. You have belief on your side. You know that my future is fleeting, my grandiose plans, an illusion, but you’ll be living forever in your dream. Damn, what a fool I am. The world for you is ethereal—eternal. This life is only a test to get to the real thing: the supernatural reality — Eden itself. In the study of being and essence, you are the spirit. “Human being” means “being” by any other inconvenient means. No?
But then
Why not go Directly to the Promised Land
Bypass the Filthy Lucre of this Material Existence?
Just Leave it to Us Unbelievers!
If a creationist’s Creator created this mess and it’s a sleight of hand to see if individual souls will waiver or whether they’re good enough for the afterlife, then it’s an ecclesiastic experiment. Do you hear how mad it all sounds? Whatever life is, and the choices diminish with every passing advance of cosmology, it is surely not a lottery of some divine casino owner. But where does matter come from? Mr Multiverse? I don’t know exactly why or where the wind blows. Is it a wind god that looks after it? And if there is no wind god then how can there be a multiverse god? To refuse the one is to decline the other  but no, instead reality is rejected as a false representation of the “real” supernatural reality. Existence from nothing sounds absurd and a rational super creator sprung from nowhere sounds logical?  By any standard, that’s upside-down. Supernatural reality is all the more real to carts without wheels. If you have “wheels” and can tolerate living with the unanswered big “Why” question, then you have a shot at the proper purpose of life. Your reward being “Going After the moral treasure of life and that is, whatever is worth every effort to achieve it, especially moral character, freedom and love.
So you must write your own “good book” from the reality of the material world, but it is not anything you write per se but that which is created by your daily choices. It also shapes and creates your purpose in life. While so very difficult, thousands of wise people have left a legacy for you to follow; read their words. It’s like a continual conversation with wise thinkers or even sages. Life, to paraphrase Lucretius, is the passionate impulse to reproduce. Our reality is a universe that came alive with frenzied vigor and of which we’re lucky enough to be a part. If the atoms are eternal as Democritus suggested 2500 years ago, then everything that can be created will in time be created, but there’s a difference between something evolving from the origins of the natural universe and humankind creating a mythical explanation of the whole event. This can no longer be taken seriously except by people who believe community and religion are synonymous. These two separate forces in us may both be spontaneous outgrowths of our human nature, but they have their difficulties, especially when they’re combined. The main trouble with supernaturalism today is that – from a distance – most of the representatives of it look like buffoons whether “Reverends” or “Professors”. Worse still, the empirical or scientific problem for the divine explanation is that Democritus’ theory of atoms met Dick Feynman’s Sum Over Histories in 1948. The question that begs asking now is: “How many of those 2500 years in between were a waste of time for humankind pursuing the “political or religious perfect event”, when all we are allowed as a human being is apparent knowledge? We must and will learn to live with uncertainty, or to quote Feynman, “You see, one thing is, I can live with doubt and uncertainty and not knowing. I think it’s much more interesting to live not knowing than to have answers which might be wrong. I have approximate answers and possible beliefs and different degrees of uncertainty about different things, but I am not absolutely sure of anything and there are many things I don’t know anything about, such as, whether it means anything to ask why we’re here.”