Everything just happened. The laws that govern our universe have developed without guidance or direction. Great and almost magical leaps were taken along the evolutionary way, allowing nonplants to cross the chasm to become plants, and nonanimals to become animals. Without guidance, these beings developed brains where nonbrains had been and sensory organs where nothing like them had been. Randomness accounts for the delicate, unique composition of our planet that makes possible our existence on this oasis of life in the desert of a hostile universe.
Man is without a spirit.
His existence ends at death, just as it does for dogs and cats. Any morality that man possesses is contrived and societal in origin. There is no master plan for mankind. Our existence is an accident, our work on earth is fruitless, and our relationships with one another are ultimately meaningless. Like a pack of wild animals, we have no other purpose on earth but survival.