Willpower can be a Powerful tool in the hands of a determined, disciplined individual.  It can help you confront any problem you have and adjust your lifestyle.  However, willpower only takes us so far and then we always run out of our own strength.

Now, what happens if, instead of turning first to willpower in your time of need, you turn to God?  God releases His power into you and enables you to go all the way through to victory.  Now you're energized for positive things, but willpower does not get the credit for our success God does.

Jesus said in John 15:5 "Apart from me you can do nothing."  This is one of the most important and most difficult lessons we must learn if we want to enjoy the life Jesus died to give us.  When we turn to anything or anyone before God, He is insulted and is obligated to let us fail so we will realize that " except the Lord build the house, they labor in vain who build it."  (Ps 127:1)

We must learn to let God do the heavy lifting.  Let Him supply the ability to energize our choices.  We can choose to exercise or stop overeating, but our choice alone is not enough for complete victory.  Willpower and determination will get us started, but they've been known to quite in the middle and leave us stranded.  God never quits in the middle.