Everything in the universe is physical
We live in a universe that is constantly expanding, on a planet which holds all the life forms we know of. In the matrix, the people are alive only in a computer program while the real world rots from within. How are we to know that the world which we live in is the real world? The underlying question here is what is real, which I am going to discuss in the paragraphs below.
[C1]A materialist would argue that the universe is physical and therefore real.[P1] The problem of evil states that if god existed, he would not allow such disasters and destruction to be caused on earth, therefore there is no god. So all things that occur on Earth are based on the interaction of physical atoms. [P2] Intelligence occurs at the end of an evolutionary process, this was proved by Darwin in his theory of evolution. Therefore there is no god who creates forms of life on Earth, everything is based on motions and interactions of atoms. Therefore everything is physical. [P3] The universe is eternal and infinite there is no need for a god to create it, it forever expands by itself. There are many universes, not just this one and everything in them is real and physical, because it can all be seen by our eyes, what can be seen is not an illusion.
[C1]A on the other hand sceptics would say that the statement is unjustifiable, and would therefore suspend judgement. [P1]They would also argue that no-one could possibly see the entity of the universe and could therefore never be sure of what it is made up of. [P2]They would also then state that it is impossible to justify that non-physical things actually exist in this universe. [P3]They would also argue that other metaphysical arguments are not sound arguments and you cannot decide one side opposed to the other.