A man's ethical behavior should be based effectually on sympathy, education, and social ties; no religious basis is necessary. Man would indeed be in a poor way if he had to be restrained by fear of punishment and hope of reward after death.
The cloning of humans is on most of the lists of things to worry about from Science, along with behaviour control, genetic engineering, transplanted heads, computer poetry and the unrestrained growth of plastic flowers.
Those who restrain desire, do so because theirs is weak enough to be restrained.
A person is never as quiet or unrestrained as they seem, or as bad or good, as vulnerable or as strong, as sweet or as feisty; we are thickly layered, page lying upon page, behind simple covers. And love - it is not the book itself, but the binding. It can rip us apart or hold us together...Layers, by their nature, are fragile things.