Is a Natural Explanation Always more Probable?

[Pieman333272]

I've heard often, for a variety of different discussions, that a natural explanation for something is always more probable than a Supernatural one (God). So I'm asking, does this apply to the Universe's creation and fine-tuning? I mean, is any theory, M-Theory, uncaused Multiverse, random energy shifts, etc. automatically more probable than God so long as they are plausible? I would think no, and that it is based on the evidence or premises too, but I would like to hear some opinions on this.