There are some barriers that we do not possess the ability to get through. These require supernatural powers found only with God.
Our will is only so strong and as our souls remain in these bodies we are slaves to it. We pray and practice to be not of the flesh but can a fish live outside of the water? We without air. Such it is with us and the flesh.
Yet we can still deny ourselves the desires. We can still fast and sacrifice our vices to the lord. We can feel the want and pain as he does for the lost each day.
To fast is to remind ourselves of the power of God and our dependence on him for everything.
Mark K.