Some things cannot be "proven" absolutely, but are accepted as fact based on compelling evidence. For example, a couple meets as children, grow up as neighbors, go to school together, get married, raise a family, were happily married to each other until they died in their 90's. Did they love each other? The answer appears to be obvious, but the only proof you could offer is "evidence" based on observation. It's not very scientific, but we accept it as fact.

Likewise, there is a sh!!load of compelling evidence for the spiritual realm as well. We can recognize and accept it or not....it's our choice.