A few weeks ago a skeptic asked me about my concerns with the multiverse as an explanation for the beginning and fine-tuning of the universe. He stated that he did not want a scientific critique, though, because he believes that the multiverse is outside the ability of science to test. He was more interested in my philosophical concerns. Four issues come to mind. None of them remove the possibility of a multiverse in a theistic world; however, two make the multiverse unpalatable in a naturalistic world, and the other two do remove it from possibility in a naturalistic world.
I will start by showing the power of the multiverse as an explanation, and at the same time I will show how two of the issues make a naturalistic multiverse impossible as a naturalistic explanation (but do not necessarily rule it out). I will then describe the two issues that make the naturalistic multiverse even less desirable as an explanation. Finally, I will conclude by demonstrating how all these issues are consistently and comfortably resolved by a theistic worldview (with or without a multiverse).