Here's a little story I heard a long time ago. There are several variations, so I'll just do the best sounding one.
One day, there was a terrible hurricane. The river near this fellow's house starting rising, so he went onto the porch. While watching the waters continue to rise, some of his neighbors walked by in waders and offered to help him to safety.
"No" he replied. "I'll leave it up to God". They left.
The water continued to rise, so the man got on his roof. Moments later, a boat comes around, and offers to carry him to safety. He declines, stating "I am trusting in God".
Eventually, the water rose so high, that the man was forced to stand on top of his chimney. When the water was up to his chin, a helicopter came by and lowered a rope. He ignores it, believing that God will help him through this situation.
He soon drowns, and is able to ask God in person why he didn't help him. God tells him that he sent the mans neighbors, a boat, and a helicopter.
So here's my point. It's fine and dandy to say that you left it up to God, and since you failed, then it must be God's will that you do something else. I find that to be a self serving and pitiful excuse. God gave you the tools to do it; it's up to you to use them to get the job done.