The life state presented by the limited life journey from birth to return is the fate of mankind.
Believe me, it's not up to me.
It is up to me. It's not up to God to decide.
It means that I control my own destiny and don't want to let God decide. It describes that people do not bow to fate and have the spirit of resisting fate. The initiative in life is in one's own hands, emphasizing that personal life should be grasped and changed, which can be decided by oneself, not by heaven and earth.