Since the Universe we live in is a part of the mind of God:

 If we assume God to be literally infinite then believing that there are multiple universes or even an infinite number of universes might be useful.

My experience as a Sanctioned Soul traveler throughout this Galaxy is that everything wouldn't work the way it actually does unless we were living inside God's mind somehow.

As a direct result of this it is therefore likely that there could be an infinite amount of Universes inside God's mind and not just one.

By God's Grace

Just because earth and other planets appear to be physical doesn't mean that they are.

For example, if you were living in a heaven realm you would believe that is real too and you would be right.

By God's Grace