Well first of all it's a business and it's a tough business and you have to have the strength to survive all the set backs all the failures that make this a mean business that's getting meaner and meaner every year in my opinion.
If you tell God no because He won't explain the reason He wants you to do something you are actually hindering His blessing. But when you say yes to Him all of heaven opens to pour out His goodness and reward your obedience. What matters more than material blessings are the things He is teaching us in our spirit.