Ethics is a subject studied since the days of Plato and Aristotle. The word "ethics" is, in fact, derived from the Greek ethos, meaning habit or custom. Theological ethics, as a distinct branch within the study of ethics, seeks to understand, not behavior, but being. Often, when discussing theological ethics, the individual is referring to Christian ethics, but it should be noted that all religions promote a system of ethics.
Christian ethics, as illustrative of theological ethics, defines right and wrong behavior from its particular religious perspective. Christian ethics is derived largely from the Bible, both the Hebrew Old Testament and the New Testament from the early first century. However, even reliance on the Bible as the main source of ethics has led to a number of different interpretations within the Christian tradition.
Regardless of the religion promoting its particular ethical system, theological ethics in general stems from its essential idea that God or the gods is the source of right and wrong. God or the gods command how people should behave. This is the divine command theory of morality. Theological ethics can be therefore contrasted with naturalistic ethics, which start from the premise that human action should be based on human reason. There can be, however, a close approximation between naturalistic and theological ethics, particularly in the view that God wants humans to use their reason to figure out the most moral way to live.