It is widely assumed that theism is superior to metaphysical naturalism in explaining moral phenomena, especially with regard to the practical aspect of morality. In this article, I will firstly clarify what this practical aspect amounts to and present two challenges against metaphysical naturalism, by John Mackie and Richard Joyce. Then, I will critically engage with two main attempts to argue for the superiority of theism over metaphysical naturalism: One of them is the appeal to the existence of afterlife, and (...) the other is Robert Merrihew Adams’ divine command metaethics. I will argue that both are problematic for different reasons. Relying on the main aspects of Adams’ metaethical framework, I will advance my proposal to maintain the practical aspect of morality which lends theism superiority over metaphysical naturalism, and then follow with certain implications of the proposal for theistic metaethics. (shrink)