Ethis, as defined by dictionary.com, are
1. a system of moral principles: the ethics of a culture.
2.the rules of conduct recognized in respect to a particular class of human actions or a particular group, culture, etc.: medical ethics; Christian ethics.
3. moral principles, as of an individual: His ethics forbade betrayal of a confidence.
4. ( usually used with a singular verb ) that branch of philosophy dealing with values relating to human conduct, with respect to the rightness and wrongness of certain actions and to the goodness and badness of the motives and ends of such actions.
And I believe this is a good definition. It implies that different people have different ethics, there is no one set standard. I, for example, believe abortion is murder. Other people will disagree with that stance, but not consider that against their own ethical standard.
The Bible, for example, contains what many Christians would call their standard of ethics. Other religions have different standards.
My point is Ethics are only a standard for the person defining them. The Bible, to continue my example, is a set standard, whether or not I had chosen to believe it.