As for how people's fate is decided, according to China's tradition, it is that people's fate is governed by the law of cause and effect, that is, the so-called "good is rewarded with good, and evil with evil". Of course, the good and evil here are not just about this life, but from the perspective of many generations. If we look at it from the perspective of causality, then the efforts in this life can certainly change the fate, because every behavior has a cause, because there are consequences naturally, but different behaviors have different efforts to change the fate. Some behaviors have great influence, while others have little influence; Some effects are immediate, and some effects may take a long time to see.
So if you believe in cause and effect, it should be said that people's thoughts and actions affect their fate, and the eight characters reflect the fate of a person's life. There are also times when the eight characters are not allowed, that is, when someone's behavior in this life greatly affects his fate.
Of course, if you don't believe in cause and effect, all this is nonsense.