[Locked] Do you believe in Parallel/Alternate Universes?

It states that there are countless worlds, identical but somewhat different from ours.
Any fellow believer to this?
Is it a theory or an actual phenomenon?
Religion aside because I am a theist myself.

There are no hard evidence on this topic, so i will say no. But this might change perhaps, if time travel is possible*

*reference to back to the future and steins;gate