It seems from this that you don't know what a conscience is or how in acts in those that do. Conscience compels those who cultivate one to do right as they understand it. Those with a mature, well-developed conscience desire to do good and feel good when they do. If they do harm, even inadvertently, they suffer remorse and shame.
You may be intending to demean atheists, but I don't think that's what you actually accomplished. Have you seen this? :
"Atheist are routinely asked how people will know not to rape and murder without religion telling them not to do it, especially a religion that backs up the orders with threats of hell. Believers, listen to me carefully when I say this: When you use this argument, you terrify atheists. We hear you saying that the only thing standing between you and Ted Bundy is a flimsy belief in a supernatural being made up by pre-literate people trying to figure out where the rain came from. This is not very reassuring if you're trying to argue from a position of moral superiority." - Amanda Marcotte
You may never know, but others do. I do. I know where my morals come from - me, by the application of reason to compassion. There are some overlaps with probably every other moral code, but that's either because the people who wrote those used the same method long ago and writing down as a commandment from a deity, or coincidence. Religions have no good ideas not generated by this method, and fall short of what rational ethics generates, which is why secular humanists have been able to improve on biblical ethics, for example, which advocates for the divine right of kings and lays out the rules for slavery.