Can morality exist without God? I have not heard anyone give an explanation of how this could be so without having to change the definition of morality.
My own definition of Morality is doing the right thing
even when no-one’s looking.
Consider two institutions.
In one, the populace does not go around raping, killing, thieving (or eating shellfish) even though there’s no surveillance and no police force. If someone in authority told one to eat a prawn, they would refuse on moral grounds.
In the other, a prison, the only thing preventing the populace from raping, killing, thieving (not forgetting eating shellfish) is 24/7 video surveillance, backed up by police with flamethrowers who will use them at the slightest hint of any infraction. If someone in authority told them that just for the next 5 minutes they were allowed to do anything they liked, they’d instantly rape, thieve, murder and wolf down a dozen oysters.
The external behaviour of both groups is identical: but by my definition, only the first is acting morally (even though I think eating prawns and oysters is fine).
In a Universe where there is an omniscient God, who notes even the sparrow’s fall, and who guarantees eternal, inescapable and inexorable punishment for sin by casting the sinners into the fires of Hell for eternity… then I contend that there can be no morality, only obedience compelled by fear of punishment.
Only the atheist, who does not believe in an “invisible sky policeman” as he mockingly calls the Almighty, and yet adheres to Christian principles of charity to his fellow human, who never shoplifts even when the cameras are broken, and who follows the Golden Rule can be said to be “moral”. Doing Good for it’s own sake, because good is its own reward.
Such a person would be a Kantian Realist, even if he’d never heard of the “categorical imperative”. And despite not having faith in God, he has faith in Good. And if some deity told him to go put babies - or shrimp - on the barbecue, he would refuse,
even if it meant eternal damnation. Because it wouldn’t be right.