Part of the definition of Scientific Materialism in the glossary of Not-Two Is Peace is:
"...the basic presumption of [scientific materialism] is that the material world is all that exists...."

You asked, "What evidence is there that this belief system is false?"

One evidence that there is more to reality than just what we can see are the multitude of near-death and out-of-body experiences that have underlying patterns.  The advancement of medicine and our improving abilities to snatch people back from death, has brought out thousands of people who report very similar experiences of other dimensions where the spirits of men (including dead relatives) live and interact. 

Any truly objective scientist, seeing the massive amounts of reports of near-death experiences (NDEs), and the common elements between them, should be able to inductively conclude that more exists than the material world alone.  Unfortunately, the left-brain-focused scientific establishment is strongly adverse to any evidence which would challenge it's currently adopted tenets, especially materialism.