but my life now, my whole life apart from anything that can happen to me, every minute of it is no more meaningless, as it was before, but it has the positive meaning of goodness, which I have the power to put into it.
The purpose of life is to bring forth goodness. Now, in this life.
If goodness has causes, it is not goodness; if it has effects, a reward, it is not goodness either. So goodness is outside the chain of cause and effect.