I think most atheists and otherwise non-religious people would agree; one of the most common questions we’re asked is “Where do you get your morals from?” Often the question is an honest inquiry, a question open to discussion and open to the possibility that morality and ethics are constructed. But more often than not the question is meant as a challenge — surely morality can only come from a supreme lawmaker, right? I don’t have to get into the obvious answer here. The answer is so obvious that my cognitive dissonance makes it difficult for me to believe cognitive dissonance is strong enough to shield the answer from certain people.

Let’s take murder. The answer is so obvious that I don’t have to write a single word about how we know murder is wrong without god. The answer is so obvious that all I must do is attach a single image of a murder victim to this post and be done with it.

Source: Wikipedia article Avijit Roy