The body more or less relies on the soul and in my opinion should be perceived as more important as it has more meaning than the body and can do more than the body. Your soul has been through more than your body ever will. If you believe we are reincarnated, then you know our souls have been through many bodies and know that they have travelled many places. The soul cannot die. The phrase "A healthy mind in a healthy body" expresses that physical activity is important to keep the body and mind healthy.
Hope this helps but I don't know exactly what I'm working with here.
Personally from my own perspective the meaning of this quote is how some people put on a mask to make other people happy and or so other people don't notice how sad/empty they feel.
