Can people change other people's extremely rooted beliefs? I can describe your ailment in four words: you are narrow minded. You're right in that we must construct our world around things we know in contrast to that we don't. Afterall: there is a infinite amount of ways something isn't but a (theoretical?) finite limit to ways it can be described or used. But it's a human folly to assume that since something hasn't come to be demonstrated then casually it doesn't exist.
What are your thoughts on multiple universes/realities coexisting? I find it a fun thought. What if Napoleon hadn't held his troops back at Waterloo? What if JW Booth's pistol misfired? The social construct we find ourselves in is just that. A construct. A building of ideas that can be dismantled and reassembled at will.
What we can see is only a infinitesimally small amount of what defines existence. We are mere apes that in comparison to the universe and meaningless in our comprehension of it. You, me, and everyone on this board are nothing more than cavemen and women with fancy glass, metal, and plastic.
So who the hell are you to say you know what it means to define existence? If there is a god, I couldn't prove it. If there isn't then you couldn't prove it. Thus both are rational observations given that both are unverifiable theories.
What we can see and measure is such a small amount of what makes up our reality. A mere 5% of the mass of the universe is composed of matter that we can interact with. The remaining 95% of the mass is composed of dark matter/energy. So smart guy: what does that tell you?