In other words, murder is murder because of the consequences regardless of beliefs or values. Christ taught morality in that manner. Therefore atheists and nonbelievers are bound by moral laws regardless of what they say, and the laws never change. The consequences are the evidence. Morality always produces certain results which no one can defy.
Sin always destroys the perpetrators.
They must always conceal, deny and rationalize sin trying to avoid the consequences of justice. What people try to prevent from happening to themselves becomes the morality that applies to everyone. Of course not. So murder is morally wrong. God himself cannot change what morality is, because people determine what it is in their reactions.