The principles of right and wrong conduct; the basis for doing what is right, and the discernment of what is right, are fundamental issues throughout the Bible. Indeed many readers of the Bible would find it hard to separate the religion from the morality: certain actions are forbidden by God (such as murder) because they are wrong in themselves. The prophets of the OT repeatedly call for a just society where the poor are not oppressed and bribery is outlawed—principles of behaviour which are fundamental and more important than sacrifices and burnt offerings (Hos. 6: 6). And yet there are also some injunctions (such as the fourth of the Ten Commandments, to keep holy the Sabbath day) which are entirely religious and not part of a universal moral law (sometimes referred to as ‘natural law’).
It is widely held today that religion and ethics are two separate areas of human awareness, and each has its own autonomy. It is perfectly possible for a non‐religious person to have lofty ethical principles, and it is possible for a religious believer to adopt standards of behaviour which are alien to an informed conscience. There are examples in the OT of appalling barbarity performed in the name of God, as when Samuel hewed Agag in pieces before the Lord (1 Sam. 15: 33) or the Levite cut up his concubine (Judg. 19: 29). On the other hand it was a religious insight which forbade human sacrifice, when Abraham's hand was arrested in the very act of killing his son Isaac (Gen. 22: 12); but it was invoking civilized rules of warfare rather than the voice of God which saved the lives of the trapped Aramaeans in Samaria (2 Kgs. 6: 22).
While, then, religion and ethics even in the Bible are to be regarded as distinct, plainly the relationship is close and there is much overlapping. The Bible often reminds us of what by nature we already know, but it could be affirmed that moral striving receives from belief in God a measure of hopefulness which supplies it with dynamic; in the OT this hopefulness springs from the covenant which God has made with Israel; it is part of the vision of a way of life.
Some modern conservative, or fundamentalist, scholars condone moral standards in the OT which liberal Christians and non‐believers find totally unacceptable. For example, the OT enjoins holy war: the Canaanite inhabitants are to be exterminated by the invading Israelites. So it has been argued that those people were rightly to be destroyed in order that Israel, and therefore the rest of the world, should be protected from the corrupting evil practices of the people of the land. Similarly, fundamentalist writers have approved of severe punishment for homosexual behaviour (Lev. 20: 13), though they are less overt about demanding punishment for breaking Sabbath regulations or the prohibition of usury on which a free‐market economy depends.
Most readers of the OT today, however, find it hard to regard the OT as an unambiguous ethical authority, and they prefer the moral consensus of a modern democratic society which has been influenced by the NT. The command to ‘be fruitful, multiply and fill the earth’ (Gen. 1: 28) has for them no validity in an over‐populated world. They reject the OT attitude establishing both the subjection of women and the system of slavery. It is, however, evident that moral advances were made in the history of Israel as the primitive and barbaric tribes were instructed by the prophets and influenced by other peoples of the ancient Middle East; it is noticeable how far advanced were some Israelite moral principles—such as the response to the crime of theft, which was not that the perpetrator should be physically punished but that the victim should be compensated (Exod. 22: 1), because for the Hebrews assaults against the person were more serious than crimes against property, and among persons there was an equality about their rights. Even slaves were not treated as mere things.
Confidence in its status as the covenant people of God gave Israel inspiration for personal and social behaviour. It became the model for a life of responsibility in family relationships, in business, and in government. In the NT admission to the Kingdom requires a certain kind of behaviour (Mark 10: 24–5), which is succinctly defined as the twofold love of God and neighbour (Mark 12: 29–31), including one's enemies. Jesus' call to discipleship involved both a rigorous challenge in imitation of the life of Jesus himself in total self‐regard, combined with total compassion and love which transcended barriers of gender, race, belief, or social status. By actions and teaching Jesus brought into existence a community of forgiveness. It is spelt out by Jesus: women are disciples no less than men (Luke 8: 1–3), care is for anyone in need (Luke 10: 37), enemies are to be loved (Matt. 5: 44), and legal authorities are to be respected (Mark 12: 13–17). But in so far as the Kingdom is to be consummated in the future, some of the ethical injunctions cannot be practised in this present life. They represent ideals to which disciples can only approximate: non‐resistance to evil (Matt. 5: 39), total perfection (Matt. 5: 48), rejection of money (Luke 16: 13–15).
Much of the ethical teaching in the epistles corresponds to that of the Stoics and other philosophers and is part of the ‘natural law’. Paul supplies a motivation when he emphasizes the ‘law of Christ’ (Rom. 13: 8–10), which is to love one another (John 13: 34). See sermon on the mount.