Human thought has swung between two extremes with regard to the physical body. One extreme materialistic view is to regard the body as everything, as if the body is the man and with the death of the body, the person also dies.
On the other extreme is the ascetic view that the body is the carrier of all kinds of difficulties, a burden that the soul carries helplessly like a necessary evil that must be shed one day permanently once one has used it as a seat to discover the true Self. It has then to be discarded as a worn out dress or a tool whose utility is over.
The body is indeed a tool, a very intricate tool evolved over millenniums. Its purpose is to bring out higher and higher possibilities out of itself from a tiny virus to unicellular organisms to more and more complex plants, animals and now man. It can be thus seen as an evolutionary workshop where various cosmic forces labour to bring out new creatures. Going by this logic, the body is destined to evolve still higher and higher forms ultimately towards a divine body.
We have to therefore neither disdain the body nor become so attached to it as if it were everything. Instead we should take it as a tool and instrument of the Divine within us and hence keep it healthy and strong so that God can use it for His purposes.
Affectionately,
Alok Da