Bertrand Russell on Divine command theory
Russell used the Euthyphro dilemma to argue that morality cannot depend on God's commands without becoming arbitrary.
Russell's treatment of divine command theory is rooted in the Euthyphro dilemma, which he considered decisive. In Why I Am Not a Christian, he posed the question plainly: do the gods approve of certain actions because those actions are good, or are certain actions good because the gods approve of them? If the former, then goodness is independent of God and we do not need him. If the latter, then goodness is arbitrary — God could have declared cruelty a virtue.
Russell regarded this dilemma as genuinely ancient — it had been a problem since Plato — and genuinely unsolved by any theologian. The various attempts to escape it (by identifying God's nature with the good, or by claiming that God necessarily wills the good) struck Russell as sophistical. They relocated the problem without solving it: if God's nature is necessarily good, then goodness is a standard that exists independently of God's will.
Beyond the philosophical argument, Russell made the practical observation that people who claim to derive their morals from God invariably select which divine commands to follow. Christians do not stone adulterers or execute Sabbath-breakers. The fact that they use moral judgment to filter scripture proves that their moral judgment is prior to — and independent of — divine command.
“If you are going to say, as the theologians do, that God is good, you must then say that right and wrong have some meaning which is independent of God's fiat.”