"If you believe, there will be, if you don't believe, there will be nothing" is a vernacular, which can't reach the philosophical level and is logically unreasonable, because consciousness reacts on matter.

"I saw the table, it doesn't exist. If I can't see it, it doesn't exist. " Harmony is a theoretical basis.

From the perspective of human understanding, that's it. Just like a substance, you think it is like this now, but with the development of science, it has become like that again. Matter itself has not changed, but knowledge is changing.