The Euthyphro Dilemma is a philosophical problem first posed in Plato's dialogue Euthyphro.
The Dilemma
Is what is morally good commanded by God because it is morally good?
Or is it morally good because it is commanded by God?
"The point which I should first wish to understand is whether the pious or holy is beloved by the gods because it is holy, or holy because it is beloved of the gods."
Plato, Euthyphro
Against the First Horn
God's Omnipotence: If morality is independent of God, it seems to place a limitation on God's power and sovereignty.
God's Nature: The idea that God depends on an external standard of goodness appears to conflict with the concept of God's self-existence.
Epistemological Concerns: If moral truths are independent of God, how can we as humans come to know them reliably?
Against the Second Horn
Arbitrariness: If what is good is simply what God commands, morality becomes arbitrary. God could, theoretically, command the worst creulty imaginable (eternal conscious torment), and it would be deemed good.
Tautology: The statement "God is good" becomes tautological and loses its meaning, as goodness is defined as whatever God commands.
Epistemology: If true, how we can know God's commands? What do we do when the Bible conflicts with our moral intuitions?
Divine Nature: If God's nature is good, and God cannot act against His nature, then there is a standard of goodness (God's nature) that is independent of God's commands.