I am not an advocate of Divine Command Theory, but one objection to it that has some popularity with the new atheists is that following such a moral view is childish. The claim is that such a view is childish because the person who accepts and operates under such a framework is not freely deciding which moral principles to accept and follow. Unlike the mature moral individual, who weighs the arguments for and against accepting some moral principle, the follower of some form of divine command theory just accepts whatever divine commands are present in her favored religion. She does not reason about them, consider their significance, but rather she just blindly and irrationally follows them.
But this view of the divine command theorist is incorrect. A follower of some form of divine command theory can still exhibit moral autonomy and rationality, in the following sense. She may not be imposing a moral law on herself, but she can exercise moral autonomy by deciding which putative divine commands are genuine divine commands, judging which interpretations of those commands are correct, determining the implications the particular commands have, and reflecting upon how best to apply those commands into her specific circumstances. This requires much more than proof-texting to support one’s political, social, or moral views.
The divine command theorist can still be self-governing in the moral realm, by autonomously choosing to be governed in that realm by another Self.
This sort of approach would require the intellectual virtues of carefulness, tenacity, fair-mindedness, humility, honesty, and courage, among others. These are not “childish” traits, but rather are central traits of the excellent mind.