In order to function properly as sophisticated biological machines, we need motivation. In as much as humans have developed consciousness, our motivational setting does not just depend on instincts but on cognition as well.
As far as motivation is concerned, lower animals get by just fine being driven by their instincts for survival and reproduction. The more humans, as higher animals, develop consciousness, the more we question "Why do we live?" and "What is death?"
Cognition is a philosophical and psychological category closely related to consciousness. While self-consciousness is just a state of having some ideas about oneself, self-cognition would be to have correct ideas about oneself.
Religious lunatics do have self-consciousness; they clearly have some reflective ideas about themselves, and their position in the universe. But from a scientific perspective, they are objectively wrong.
In as much as we now know that all religions are just inventions, and in as much as we are aware that we all are just the results of biological evolution, we actually have evolved enormously over the past few hundred years. Because of our cultural achievements in explaining the world and our origin, humans have evolved into a species with cognitive capacities way beyond of what our ancestors of just 20 generations ago possessed.
And our advanced cognitive capabilities teach us one thing (whether the individual members of a species understand this or not): anytime we are not preoccupied with tasks of survival, we pursue matters of reproduction, just as lower animals do.
Reproductive behavior (or, more clearly: having sex) is the only meaningful endeavor we can pursue, or the only thing that provides philosophical "meaning" in life. It is the only human activity that is synchronized with evolution. Religions, ethics, and morals are delusions.
Are you still with me?
We will live our lives because we have been born (certainly not by our own choosing). From both a logical and biological perspective, the only "philosophical meaning" that is available to us, is to pursue optimal sexual satisfaction, and to do so consciously (and cognitively), and to hope to end it all with a gentle, unconscious death. Nothing remains.
