Does your life have purpose, a reason for being? The answer to that question is really dependant on the existence of an intentional creator; a creator for this universe, and so, indirectly, you. Is this universe and all it contains the product of a creator; God? Or is it just the product of random chance?
Most people I have talked with seem to feel like their life has purpose; purpose gives meaning to life, and it keeps me going when life isn't fun. Google defines purpose as "the reason for which something is done or created or for which something exists." My purpose as a human is based on the reason for which I exist. So just why do we exist?
I am convinced that this universe, and my life, were created by God, and that he had a reason for doing so. I believe that reason has to do with preparing me, and others like me, for a life with him that extends beyond this universe. God's purposeful creation gives my life purpose, a reason for being. I exist because God made me, and he made me for a reason.
But what if there is no creator? What if all we see is the product of blind chance? Naturalism is a philosophy that operates under the assumption that all that is, is the result of natural processes, that there is no supernatural agent responsible for creation. This is the position of atheists, as well as others who reject that the universe was intentionally created.
Now if naturalism is true, and we are simply the product of blind chance operating through natural processes, does life have any purpose? To the naturalist, life is nothing more than a series of complex chemical reactions, that just happen. It has no reason for its existence, and thus no purpose. We are fundamentally no different than a bug or a rock.
But does it really matter if I have a purpose for being or not? I believe it does. If I have no purpose, then does it really matter what I do or how I live my life? After all, my life is really little more than an accident, and will soon be over. And nothing I have done, or failed to do, will really matter. If I was to find a cure for cancer, or go down in history as the worst mass murderer, what would it matter? If I, as well as those around me, are nothing more than minor blimps in cosmic history, with no purpose and no significance, then it does not matter whether I lived or not. My life has even less purpose than the science experiment performed by a high school chemistry student, which at least is conducted for a purpose.
But it is hard to live like that. I want to believe that my life has some purpose, that what I do really matters. And so I invent purpose for myself. I convince myself that I need to leave the world a better place than how I found it. Or I set my purpose to be enjoying life to its fullest, experiencing all that the world has too offer. But regardless the purpose I set for myself, whether self centered or others centered, it is not really the purpose that I exist for. That purpose simply does not exist, at least not if we are only the product of blind chance.
Trying to live life as if it had purpose, while at the same time holding to naturalism is irrational, an incoherent worldview. The only way ones life can have any real purpose is if it exists for a reason. And there can be no reason for our existence apart from an intentional creator. It is the creator who gives us purpose. There is no other way. We cannot give ourselves real purpose.