At very small scales the question of the reality of a theory is less important than its ability to predict outcomes. Quantum mechanics for example doesn’t make sense if you think closely about what particle waves are. However, its predictions are rock solid. So solid that when experiments like the Einstein–Podolsky–Rosen paradox were thought up to falsify it, it ended up providing further evidence for it.
So if String theory makes predictions about reality that turn out to be true then you use it. An example might be the troubling area of quantum entanglement in which particles far away from each other still seem to be still connected. Tiny dimensions provides one way to think about how this might be possible. Basically while they are far apart in three dimensions, they are still close in some of the others.
Also, a hypothesis is not the same thing as a theory. A theory has evidence, while a hypothesis is conjecture. So the multi-universe hypothesis is conjecture at this point. That this distinction often gets lost when the concept is in the media.
However, it may eventually be testable. The general thinking is that the comparative weakness of gravity might happen because gravity leaks between universes. So really accurate measurements of gravity might provide evidence for other universes. The possibility of being falsifiable is what makes it different from the concept of the supernatural which by definition can never be falsified.

If you were to speak with a quantum physicist, and that’s not something I do every day, although I do every few months, you might get an interesting discussion of how not only can the body be resurrected after death, it absolutely, in terms of quantum physics, will. I don’t think they have equations for souls, however.

Robert R., I’m guessing you’re talking about the concept of quantum immortality. This is only possibly in the many worlds interpretation of quantum mechanics. Not everyone who accepts many worlds also accepts quantum immortality.
Google it for better details, but the basic idea is that the multi-verse exists and what we see as particle wave duality are touch points between the many worlds. In many worlds every possible outcome that can happen eventually does happen because the number of universes is infinite. Including (if physically possible) living forever, at least from your own point of view.
There’s even an experiment called the quantum suicide experiment which could falsify the concept from your own point of view. But no sane person wants to try it. However, if it’s true you could do things like ensure you win the lotto drawing.
An addendum to my prior post. String theorists didn’t pick eleven dimension because they were Spinal Tap fans. The extra dimensions were added to avoid the existence of three dimensional point particles by giving them size in the other dimension. Basically it was done to avoid dividing by zero and make the math work out, but had implications that were attractive, so the idea stuck.

It is interesting how new theories and theoretical predictions are being created based on unproven theories such as String theory. More speculative physics piled upon more speculative theory. The only difference between this idea and crackpot theories is a serious amount of mathematics was used to support it. We are using unproven mathematics to establish un-provable theories. Perhaps we should try coming back down to Earth and reign in this Mad Science. If you are growing tired of all these questionable theoretical concepts spewing from the popular media outlets try checking out The Theory of Super Relativity.
Einstein was right about the shortcomings of Quantum Mechanics and so therefore String Theory is also the incorrect approach. As an alternative to Quantum Theory there is a new theory that describes and explains the mysteries of physical reality. While not disrespecting the value of Quantum Mechanics as a tool to explain the role of quanta in our universe this theory states that there is also a classical explanation for the paradoxes such as EPR and the Wave-Particle Duality. The Theory is called the Theory of Super Relativity. This theory is a philosophical attempt to reconnect the physical universe to realism and deterministic concepts. It explains the mysterious. http://www.superrelativity.org

If you somehow WANT something to be true, this desire alone disqualifies you from having relevant opinions about science. Science is a bag of methods that will lead you to answers and new questions, peoples feelings about results doesn’t change the results in any way (unless dishonesty is involved) and are merely time consuming obstacles for actual work.
Either you follow the methods (gravity AND Darwin) or not (no gravity AND some other silly theory)

While it’s very true that String Theory has not been proven, it’s not that scientists are pulling these theories completely out of thin air, either. String theory has been painstakingly developed over the years by physicists working to make a theory that is fully consistent with current experimental evidence, matching the existing theories about natural laws, but extending those theories into new realms. (I discuss all of this in my recent book STRING THEORY FOR DUMMIES, by the way.)
Some scientists take some theoretical physics findings as evidence that the universe evolves without the need of any sort of deity. This is obviously far outside the realm of what science can speak about, even in theory. The Bible, no matter how long you analyze it, will never teach you how to build a particle collider. Similarly, a particle collider will never give you guidance on how to deal with suffering in your life or live a moral life. Science is a methodology to answer certain questions, and religion is a methodology to answer certain other questions.

And, of course, if you’d like to buy STRING THEORY FOR DUMMIES, here’s a link!