I don't believe there is anything beyond the material in this world - and that there is only this world. This doesn't make me bitter or a capitalist or amoral, all often suggested as the only possible modes of existence in the absence of some 'higher' belief.
Of course the original question comes from a Christian/Judaic point of view which postulates there is only one God, supreme over all creation. Logically, there might be an argument that there was a Creator, a supreme being who created all things and now presides over them. But if you accept the (to me) highly implausible argument, that there can be higher forms of existence on a divine plane, I find the argiument to restrict such beings to a single form a nonsense. If I was ever tempted to believe in the possibility of a divine being, I would be obliged to believe in a multi-theistic universe, populated by many divine entities - we might call them spirits or gods or whatever. How could there possibly be just one?
Don't be tempted to think we are far away, two millennia away, from such beliefs, and that they are therefore 'primitive'. This would be a horribly Euro-centric and patronising mistake. Many sophisticated communities and peoples around the world, numbering millions of pindividuals, believe in more than a single God.
And at some level, we acknowledge the possibility - next time you throw a penny in a well or a fountain, think about what your're doing and why.