For example, say you're leaving a restaurant and you spot a ten dollar tip passing by a table.
The enticement of increased wealth without much effort sure is tempting. By simply extending your arm and inconspicuously grabbing the cash, you will be ten dollars richer. Since no one is looking, you won't get into trouble. Plus, the waiter probably wasn't expecting such a large tip anyway. Where's the harm in that?
In this case, a Christian or a Jew would point to the Ten Commandments: "Thou shalt not steal." According to the Christian/Jewish point-of-view, this alone will restrain a religiously devout individual from snatching the money off the table. This follows the rules of deontological ethics: Something is either always right or always wrong. For example, stealing the money off the table would be morally wrong because stealing is always wrong.
However, what if the commandment said "Thou shalt steal?" Would stealing be an absolute right then? Is all that is required is a recommendation from a centuries-old text? How about the sixth commandment: "thou shalt not kill?" Does this rule apply with self-defense? Or war?
Here is the fundamental problem with static morals: the inability to judge every action we humans make with reason and free will. Shouldn't morals stand on their own merits? Humans are fantastic beings because of their ability to examine the consequences of their actions and make appropriate choices--as opposed to wild animals that act on instinct alone.
Therefore, morals do not come from religious tomes. Morals would exist nicely without them.