Divine command theory of ethics says that an act is either moral or immoral solely because God either commands us to do it or prohibits us from doing it. The only thing that makes an act morally wrong is that God prohibits doing it, and all that it means to say for example is that killing is wrong because God forbids murder. Within Devine command theory we find that it is wildly far-fetched for reasons best illustrated by the Euthyphro dilemma, which is based on a discussion of what it means for an act to be holy in Plato's Euthyphro. Substituting "moral wrongness" for "holiness" raises the dilemma “Is torture wrong because God prohibits it, or does God prohibit torture because it is already wrong?”
Devine command theory takes the first route, Euthyphro takes the last one. If a good God prohibits torture he does so because torture is intrinsically wrong, not merely because he declares torture to be wrong by deeming it that way. But then, if torture is intrinsically wrong, then it is wrong regardless of whether or not God exists. Either certain acts are wrong regardless of anyone's opinions or commands - including God's, or else all that we mean by "torture is wrong" is "God prohibits torture." Rather than grounding the objectivity of ethics, Devine command theory completely undermines it by insisting that God's commands (like those of individuals or societies) do not require justification in terms of any external principles.
Devine command theory is therefore a kind of moral relativism by saying what's right or wrong is what one's God (like one's self or one's society) says is right or wrong - and there are no moral standards apart from this. Yet if God said that 2+2=100, 2+2=100 would however be false because 2+2=4 is true regardless of what God says. The same point holds for moral propositions like "inflicting unnecessary suffering solely for fun is wrong." If that proposition is true, then it is true regardless of whether God commands or prohibits inflicting such suffering.
If there is no standard of “being morally right” apart from God’s commands, then God could literally command us to do anything and it would be right for us to do it by definition. Whatever God commands becomes the standard of moral rightness, and there are no moral standards external to God to limit what he would or would not command. So if God commanded one person to rape another, Devine command theory entails that rape would be moral because “doing the right thing” is logically equivalent to “doing what God commands”. A highly unlikely implication is that it is impossible to even imagine God commanding a wrong act. What counts as moral or immoral behaviour in Devine command theory is completely subjective and dependent on God’s authorization. Therefore while immoral things can be deemed as moral, even if requested by God, this does not change the ethical rightness of the act.
There is the belief that goodness flows from God's nature, this merely changes the form of the dilemma and raises the question “Is compassion good because it is a part of God's nature, or is compassion a part of God's nature because it is already good?” The first option produces problems parallel to those for Devine command theory. If malice were a part of God's nature, for instance, it is doubtful that malice would automatically be good. So if there were any objective and absolute moral standards that already stood independent of whatever God had to say, then a God can be either good or evil, and the assessment of a god's character, whether good or evil, would then depend upon criteria independent of any god's commands. In further detail – If God commands an action because it is good; then what is it that makes God good?