It’s often argued that you must believe in God to have objective morals. This is incorrect.
The Euthyphro Dilemma written Plato asks, “Is something morally good because god commands it, or does god command it because it is morally good?” In this case, god commands these morals because they are good – they positively benefit the beings affected by them. As such, god is completely irrelevant as to whether these morals are right and wrong – they are either right or wrong independently of whether god exists or not.
If the other is true, then there are many points we can make. Would it still be good in another universe without God?
Does Islam or any other theistic religion solve this problem? Not really. At the very least, there are multiple interpretations of Islam. Who is to say which is right and objective? Is it objective to beat your wife, to marry multiple women (rotating 1 night per wife), to stone adulterers, and so on? Is it objective morality to allow child marriage? How about ISIS’s understanding of morality? Capturing and selling disbelievers as slaves, having sex with Yazidi women (because they are war booty). Is this right?
If you say “my Islam doesn’t allow this”, then who is to say which Islam is right and wrong? Who is to say that “your Islam” is objectively moral?
It makes much more sense to look for an independent standard of morality and well-being and use that, regardless of what your holy book tells you to do so.
Also see How Morality Has the Objectivity that Matters—Without God on the Secular Humanism site:
At this point, the believer might protest, “But there has to be something more than that. Morality is not just a human institution.” Well, what is this something more? Why is it not enough to tell the wrongdoer that everyone condemns him because what he or she did violated our accepted norms, which are essential to our ability to live together in peace? Do we have to add, “Oh, by the way, God condemns you too?” Exactly what difference would that make?
What some believers (and, again, some secular ethicists) appear to want is some further fact, something that will make them more comfortable in claiming that moral norms are authoritative and binding. Somehow it is not sufficient that a norm prohibiting the gratuitous affliction of violence reduces pain and suffering and allows us to live together in peace, and has, therefore, been adopted by all human societies. No; for the believer there has to be something else. A moral norm must be grounded in something other than its beneficial effects for humans and human communities. The statement that “it was wrong for Kim to hit Stephanie” must pick out some mystical property that constitutes “wrongness.” For the believer, this further fact is usually identified as a command from God, but as we have already established, God’s commands cannot be regarded as imposing moral obligations unless we already possess a sense of right and wrong independent of his commands.