I recently "came out" as an Atheist to my Christian family. They responded well, though they asked a lot of questions about why I decided to leave the church and reject God. I explained my various grievances with the Church which they all agreed were valid points, yet hey were willing to overlook them, something I could not do.
Then my mother threw me a curveball. she said "If you have no God to hold youself accountable to, why bother being a good person, why not lie, steal and cheat?" I tried to explain how the right thing is still the right thing and how I didn't want to only to make the right choice because out of fear of punishment. I wanted to do the right thing because it was the right thing to do.
She then went on to ask me why it was the right thing to do, who said so? I responded with my conscience told me what was right. She asked me what told my conscience that right was right and wrong was wrong.
And this was where I said something along the lines of: "Uhh...buhhh...meh?"
So my question to you all is: Where do you base your morality from, and how do you defend that morality against people who believe that morality can only be based off of a God?
the way to answer it is to explain to your mother that she doesn't get her morality from god either and so she's asking the question on an incorrect assumption- "i get my morals from god, where do you get yours from?"
first. what your mother would almost certainly tell you that is key to her morality is that it provides an objective foundation to morality. but does it? ask her what she means by "objective" in this context. she's likely to respond to you by saying something that means that "objective" in this sense means to her that morality isn't grounded in the thoughts and attitudes of persons. but what is god of not a disembodied person with thoughts and attitudes of his own? and your mother would also likely tell you that what she likes about her "objective" morality is that it's universal, that it isn't relative, that it applies to all people in all places in all times. and you'd explain to her that it doesn't do this, that what people have called "theistic morality" has changed over and over again throughout human history. you'd explain further by asking her if an alien were to come to earth, this alien having the technology to be able to see the past and the future and read our minds, and we decided that the dictates of this alien were morally good would that be objective morality. she'd certainly say no but then you'd have to ask why, since this morality would be objective in the dual senses of being universal, applying to everyone, everywhere; and it wouldn't be grounded in the thoughts or attitudes of persons.
ask her what it even means to say "a transcendent disembodied omni-person grounds our morality". how does something that is so radically beyond every experience we have of the world ground morality in any way that's reliable such that we should be willing to follow it, basing our lives around it.
present to her the Euthyphro Dilemma; ask her if god defines what is good or if he describes what is good. if he defines what is good then what is good is only good insofar as god says it's good. and if he merely describes what is good then we're left wondering both where he gets his definitions of what is good and, furthermore, why we're not able to discover these definitions for ourselves. once understood we see that god-based morality is either arbitrary or irrelevant.
ask her why it is that we can conceive of a morality that would be far better than that laid out in the bible. why are our moral intuitions so much different than gods? why does he incite people to genocide and arrange the slaughter of millions? why doesn't he decry slavery and rape? why nothing about equality for women? i mean, even the ten commandments are an awful basis for morality. they refuse religious liberty and enthrone god as a spiritual dictator who would include in a list of moral dictates proscriptions against worshiping any god other than him instead of saying anything about rape or slavery.
explain to her that you're still the same person that you were yesterday and the day before. that you've felt this way for some time and yet, as she can see, you haven't been running riot, going around making horrible decisions.
ask her if she found out yesterday that god didn't exist, would she jump up, run out the door, and go start committing all sorts of atrocities. and when she of course says no then ask her why not.
ultimately, we get our moral intuitions from evolution. we get our morality from our parents and the culture we live in. and your mom does too.
The answer is quite simple: All morals worth having are based on empathy and logic, with a dash of community standards thrown in. As M pointed out, this is exactly how your mother picks her morals. If you need god to tell what is moral and force you to behave, then you are either truly psychopathic or have the mind of a small child.
To paraphrase Hitchins "I do not need to take my moral code in tablet form" when refering to 10 commandments.
Ask do you need to be commanded not to kill or steal?
Also most of the commandments are about worshiping god and not right or wrong.
Just found the video here is the (missing) link. This is all we on Earth need to know about them.
Questions of morality Predate Judaism let alone Christianity as well as existing in societies that had no contact with Judeo-christian philosophy. I'm paraphrasing here but Robert Heinlein said that morals are just rules that a society creates for its survival, which seems as good a definition as any. As to the golden rule http://www.atheistcartoons.com/?p=3701