If only human body, why sometimes lose the manifestations of wellness, such as activity and the desire for life despite the absence of his body from diseases? So there must be another moral aspect. In your opinion how to maintain the moral well-being and integrity?

If only human body, why sometimes lose the manifestations of wellness, such as activity and the desire for life despite the absence of his body from diseases?
So there must be another moral aspect.
In your opinion how to maintain the moral well-being and integrity?