I believe that, since "the fall" man has inherited a sense of what is right and wrong. That's why, short of being demonstrably insane, our judiciary holds people accountable for breaking the law...because everyone knows the difference between right and wrong, it's innate. Thus, I believe that we come fully equipped with a conscience. We can, though, ignore our conscience, at will, and justify our actions and inactions to ourselves to suit ourselves. Ah, the irony.
I also believe that we are, as humans, not completed (or fulfilled) without a personal relationship with our Creator...that God left a hole inside of all of us that can only be filled with His presence. Thus, the seekers, those who spend their lives trying one thing after another to fill the emptiness. The most pathetic ones of all are those who tell themselves that there is either no God or that each of us is God and we are therefore answerable, ultimately, only to ourselves.