An interesting implication of the multiverse theory is that it provides an answer for how we ended up with a universe with just the right combinations of gravity, electromagnetism, strong and weak nuclear forces. It's like the Goldilocks story -- tweak any of them to any other value and all matter would either repel into an nearly empty space or attract into one mass that would collapse under it's own density. There are other reasons for the multiverse theory, but under a theory of infinite multiverses, you would by definition create a universe where all the right combination of forces would come together to form our stars and planets -- including ones that can sustain life.