Atheism is the non belief in Gods. It makes no statements about morality.
Nevertheless I have been challenged - why should murder be wrong ?
{Before directly addressing the question consider the following information:
Not only are many Torah rituals paralleled in the ancient near east so are some of their laws and "morals".
From the book Essential Papers on Israel and the Ancient Near East [ANE] 1991- F. Greenspahn Editor
Beginning Page 176 "The Protection of the widow, orphan, and the poor was the common policy of the ANE".
"The policy of protection of the weak occurs also in the wisdom literature of the ANE"
Beginning Page 186 We have remarkable similarities and analogies between the conception of protection of the weak in Mesopotamian, Egyptian and Israelite literature with some minor differences. The basic conception in all that literature - protection of the weak is the will of the gods. In Mesopatmia - the gods being Shamash, Nigirsu, Ninurta. In Egypt the gods Re and Ptah. In Israel the god Yahweh. That Yahweh takes the weak under his protection is definitely not unique.
From the book Ancient Texts For The Study of The Hebrew Bible - Kenton Sparks 2005
Page 423 “It has long been recognized that the form and content of the code of Hammurabi are particularly close to the book of the covenant in Exodus 20:22-23:33. This applies not only to the content and order of the laws (see Wright) but also to matters of iconography, since Hammurabi , like Moses, is depicted receiving his laws directly from the deity atop fire-and smoke enshrouded mountain(Van Seters). The best explanation for this similarity is that the Biblical author knew the code of Hammurabi and intentionally shaped his work to mimic the older more venerated text."
Page 430 "The form and content of Hebrew laws are similar and sometimes include provisions that are nearly identical to their Near East counterparts."}
The claim is made without "God" there is no basis for morality. Even if true, it certainly does not logically follow God exists. Moreover the claim leads to several inescapable dilemmas with the result that claiming morality comes from God becomes a useless proposition.
1) Plato and Socrates - there are two options
a) A conduct is right because god commands it. OR
b) God commands the conduct because it is right.
If b), then for the conduct to be right does not require a God.
If a) then the element of arbitrariness enters, since God could have just as well said lying and murder is right. Remember under option a) it is God's command alone that makes right or wrong. If that is
the case the meaning of the words right or wrong loses all meaning. Also, any action can be justified by arguing God said so. (That has been the justification of some of the most horrible acts in the history of man.)
{ETA 1/28/2019 There is a theological response to Plato and Socrates that proposes The DEITY IS THE GOOD. As if the the Deity and good are one and the same. But then I ask is the Deity 'good' because it has the properties, attributes and characteristics of goodness ? If so then goodness is being specified independently of the Deity ! However, if the Deity is good, because to be good is to be as that Deity is, then 'goodness' is arbitrary. Whatever the characteristics of the Deity were it would be called 'good' even if the Deity was say jealous or malevolent etc:}
2) If somebody persists with option 1a ,which God shall we select ?
3) If somebody persists with option 1a whose interpretation of even a particular religious tradition should we select ?
4) Every religion based on ancient texts have ambiguities, uncertainties and contradictions. Take Judaism's command to rest on the Sabbath. The Torah and it alleged oral tradition was formed thousands of years ago and has no discussion of modern inventions. So there is a large unknown how those ancient laws are to be applied. It comes down to a human decision made in modern times and can not be claimed to be from God. And those ambiguities apply to every Torah law or command.
Moreover, the Torah itself is believed by academic scholars to be composed over many generations by different people each with a political or other agenda.
5) What if a particular religion thinks murder is permissible sometimes ? Even the Torah commands murdering innocent children under some circumstances. Some of my other posts discussed some disturbing Torah laws or commands.
6) If somebody claims a particular action is prohibited because God says so, we may ask what evidence do you have he said so, and all such evidence is not convincing.
7) It is hard to imagine a society where murder is permitted. How would it survive ?
{ETA 10/31/2015 The Ramban commentary on Genesis 6:13 explains the prohibition against violence is a rational commandment there being no need for a prophet to admonish against it. He adds in his commentary on Genesis 6:1-2 that not doing violence is a reasoned concept and does not require Torah to prohibit it. And Yehudah Halevi Al Khazri II 48 explains the rational laws [i.e. no murder] precede divine law in character and time and being indispensable in the administration of every human society.} {ETA June 2, 2017 Soncino Chumash 1968 Edition Edited by the Rev. Dr. Cohen - Beginning Page 35 - Regarding Genesis 6:13 Per Ramban “The reason that violence (robbery) is made the ground for their punishment is that all can understand the wickedness of this crime even without a special revelation.” }
8) Some moral philosophies argue for moral standards based on theories having nothing to do with God. For example:
a) Kant - Categorical Imperative (CI). An argument for absolute morality independent of God. Can your act be desired as a universal law ? {Regarding the CI "He [Kant] believed , for example that lying is never right...But Kant did not appeal to theological considerations, he relied only on rational arguments, holding reason requires that we never lie." Page 117 The Elements of Moral Philosophy1993 James Rachels second edition. } {And on page 53 of Kant's Moral Philosophy by H.B. Acton 1970 "Nor did he [Kant] think the analysis of morality showed moral laws must be commands of God - this was dismissed by Kant as 'theological morality' or 'theological ethics"}
b) Hume, Mill, Bentham - utilitarianism - right actions are those that produce on balance the greatest amount of happiness amongst all sentient beings.
c) Hobbes - Social Contract - Morality as rules rational people will accept for all their mutual benefit on the condition others follow those rules as well.
d) Plato, Aristotle, Socrates - The Ethics of Virtue. Ethics based on reason. Virtues are traits that are good for people to have. And why they are good depends on the virtue itself. For example honesty is good because without it relations with others can go awry. In addition the virtuous person will fare better in life. The virtue of fairness will help in relations between people. The virtue of perseverance will help one complete college or complete the planting of the crop in time.
e) Ethical Egoism - Do that what will truly be in your best interest over the long run.
[In short the basis of morality may lay in biological evolution see 9, human society organization, the sense of fairness, empathy, reason and self interest - none of which require God. Some Torah laws/commands come in conflict with some of those things. ]
9) The God Delusion by Richard Dawkins 2006 page 219 provides four reasons for the Darwinian origins of the moral sense (altruism, generosity, pity, empathy, decency, feelings of morality...):
First - Genetic Kinship. Second - repayment of favors; giving favors expecting payback. Third - the Darwinian benefit of the reputation for generosity and kindness. Fourth - a particular benefit of conspicuous generosity as per Israeli zoologist Zahavi.
10) It is possible God (or at least something like Yahweh) was developed by ancient societies for reasons somewhat related to morality.
In an ancient society with scarce resources and without a large police force to patrol, individuals may be tempted to commit crimes. Perhaps the threat of divine retribution encouraged people to behave so society could run smoothly. This only works if the individual believe in it, hence the need for early indoctrination and societal pressure to encourage the belief.
This divine retribution theory works not only for individuals, but for the interaction among the different tribes of ancient Israel or even with interaction among countries.
God could be invoked by leaders or people to provide justification or force for certain laws or action.
I suspect those are important reasons many religious people are afraid to give up God. God is the all knowing policeman-judge who will punish people (or countries) for evil deeds. It was noticed some evil people thrived. So, the threat of hell/after life is added to the equation. The fear is all hell will break out without the God threat.
Then again maybe not. I am not aware of any evidence that rising rates of non belief in Gods are correlated with increasing crime rates. And many crimes have been justified by religious beliefs.
{ETA 6/18/2015 I have just discovered there are studies showing there is a correlation between religiosity and 'crime' see my post Proof of God From Morality Part Two }