The multi-verse concept right now is just an unproven theory. Altho it certainly could be true, but it's too early to tell. As far as I'm aware, no one is claiming it to be absolute truth -- yet.
Global warming is a good example of how gullible people today can be, and that's with the benefit of a modern education.
So you can imagine how much more gullible folks would have been 2000 years ago!
Multi-verse is simply an effort to avoid the evidence, something like the epicycles in Ptolemy's cosmology. It is really about as scientific as astrology. People who are not religious, and I mean our secular educated, tend to believe in such faux science. Remember Nancy Reagan? Her kids are just like her, but the educated of all ages are as prone to superstition as their servants. Back in the 1850s, spiritualism in the big plantation house, (and in the White House); voodoo in the servant quarters.