Causes and effects

Many centuries ago, before history was invented, it was believed that nothing ever changes unless somebody changes it.
..... That "somebody" could be a person, or an animal, or a plant or any of the many gods who later were assigned special responsibilities, such as Venus or Mars or Hermes or (?).
..... There was PROOF that gods existed - otherwise how could anything grow, for example? Or how could the sun keep rising and setting? What made people grow old? etc.etc.
..... Then eventually all sorts of discoveries were made that made people realize that perhaps there is no God or gods, that all these changes were quite automatic; but are they? How many Gigabytes would be required to program YOUR life up to now, the size of memory required to hold all you still remember from ever since you were a baby? To program YOUR digestion/elimination system and the many other systems involved in living - and the many changes done to them interactively? What causes healing when you cut yourself? All the things involved with pregnancy? etc. etc.
..... Now that you are educated, do you really think that there must be some watchmaker making any watch, or are watches made by machines that were designed by a watchmaker and are now made quite automatically? But machines need maintenance and repairs! Do all effects have causes? What kind of causes?
..... If you believe that God exists, or gods or spirits - do you have proof of that? Or are you just accepting what OTHERS say or write to that effect?