Physical, mental and spiritual health means achieving balance and health among these three. Life is designed for growth, without growth life will decline. If you observe, when you see a newborn baby crying, you will not be angry, you will look at it with a smile and comfort it, because life is there and there is growth.
When you see a field of blooming flowers, you will feel very happy, because the blooming of flowers is growth. When you learn a very difficult skill, you will have a sense of accomplishment and joy because you have grown there.