Your statement is not true. 100 years ago we did not understand what powers the sun and the stars. Now we understand it in detail. The envelope of known science is constantly expanding and demystifying things that were previously considered mystical. In ancient times the sun was worshipped as Devine and human sacrifices were even made to the sun. Now the sun has been demystified

There are plenty of scientific hypotheses regarding what happened before the Big Bang (to the extent that time even has meaning outside of spacetime). Just type multiverse Wiki into Google. Since ancient times humanity has looked to deities to explain what is not currently understood. This is intellectually lazy.