Read this all the way through.

We cannot prove that the Material world exists. Any proof people provide is within the Material world. Example: We can measure something. True, but you're using a material means to prove that a material object exists. That's circular reasoning.

The only proof we have that the Material world exists is our own EXPERIENCE of it. And since its such a powerful experience, we assume it exists.

Likewise, the Spiritual (or non-Material) world also exists. But it is impossible to present a material proof for the non-Material, that would be an obvious Category Error (https://en.wikipedia.org/wiki/Category_mistake). What we have of the non-Material is our EXPERIENCE of it.

All we have is our experience of the world - and this includes experiences of the Material and Immaterial.