Do atheists have a conscience?
A common question put to atheists is: “Do atheists have a conscience". Yes we do. Conscience which is basically a person's moral sense of right and wrong is common to all human beings.
The ability to feel sympathy for others, the desire to care for others, build relationships and be a part of a family, the feelings we have when we see starving children or great violence - these are all an evolutionary hard wired part of who we are and it's very difficult for sane people, to see the world otherwise.
Christians have this conscience, atheists have this conscience. The only people who don't are sociopaths. So perhaps you can understand why it's so hard for many atheists to even comprehend what is being asked when Christians think that they have the monopoly on morality and accuse atheists of being in rebellion to God because they have seared their conscience.
They misunderstand evolution and ask atheists; what happened to “survival of the fittest”, why aren’t you killing and stealing to get ahead in life? These kinds of ideas are so against a human’s basic conscience that atheists are stunned when Christians honestly believe we should all be raping and murdering without God.
Therefore wither Christians like it or not, believe it or not, atheists know what is good and evil that comes from having a healthy conscience and no it has not been seared by our logical, rational and reasonable disbelief in God. We have seen the evidence or the lack thereof of God, especially when it should be there and come to an honest conclusion that there is - no personal God (abstract first causer type God is irrelevant).
But Christians don't think this is good enough. They can’t understand why an atheist would find his conscious and empathy to be of value, rather then become: like a Jacob Zuma or a Robert Mugabe or a Juluis Malema; who follow their baser instincts of selfish greed and gain. It is rather ironic that these despicable men are not atheists but believe as Christians and are waiting in anticipation for the soon return of King Jesus to Jerusalem.
You see the answer is rather simple; life with a conscience is immeasurably better, than life without one. Think about your loved ones, your best friends, even your pets. Now imagine being able to feel nothing for them, to have no real understanding of their feelings, to only care about yourself and feel an emotional deadness with regards to others. It would be a pretty boring, meaningless and ultimately perhaps even self-destructive life to live without a conscience.
When you see that conscience is an objective good for individual humans, as well as humanity in general, then you have arrived at about as "objective" an understanding of good and evil as anyone could hope for, God or no God.
References: plato.stanford.edu/entries/altruism-biological/#5