I've been told that my entire life. You can't simply ask God for a Ferrari and expect one in your driveway when you open your eyes. Besides, do you have any idea the amount of insurance you'd have to pay on a Ferrari? Do you really want that? Instead, I was told to ask God for things that would allow me to better serve Him. We see this in the garden when our example of contentment, Jesus, asks for the end of his suffering, and then concedes that He'd rather the Father's will be done, than His own.
Just a few chapters before (Luke 11), we see Christ tell his disciples to ask for anything, because those who ask will receive, those who seek will find, and to those who knock the door will be opened. So ask for whatever, because God will give it to you?
God is all around us. If there is one thing I've tried to express on this page it is a life of spiritual fulfillment is a life spent in pursuit of the presence of the Divine who is all around us all the time. God's will is moving forward and is the single most progressive, catalytic, and unstoppable force in the universe. My will--or your will--is fleeting and can be changed by what we had for lunch. Asking God to give you your will and expecting Him to do so is both a good idea and a bad idea. God promises to grant us the desires of our hearts. Jesus says if we are persistent in asking, it will be given to us. The funny thing about this promise is it's contingent on how close we are to God in the first place.
The closer you are to God, the more you find a peculiar transformation taking place. Your will and His will are becoming more and more similar. His will is becoming like your will, your will is becoming like His will until the two are nearly indistinguishable from one another. At that point, your contentment with all things will be so great that asking for change in the trivial or mundane won't cross your mind, and the things which you do ask for will be the things God has been waiting to give you all along.
God wants your will.
When the bush spoke to Moses, God asked him "what is in your hand, Moses?" (Ex. 4:2) It was a staff, because Moses tended sheep for a living. Moses was a professional leader of ornery, stubborn, stupid creatures long before he did it as a mission from God. The Lord had prepared Moses with skills and talents he could use to better serve the Kingdom and bring about God's will. It just took an argument with a shrub to convince him.
There's nothing wrong with being talented, even if your talents lie in a realm people consider "secular." Do you know what the Hebrew word for "spiritual life" was? There wasn't one. In Moses' day, the idea that one aspect of your life was spiritual and another was secular wouldn't have made sense. The ancients understood better than us the idea of a holistic experience of God in our mundane, daily lives.
If you can't experience God in what you are doing for a living, either you aren't being faithful to the way you were wired, or you aren't working with your eyes open. God loves you and made you exactly who He wants you to be. When you do your best at what you're skilled at doing, God is delighted.
God wants your skill.
We need businessmen and women, dancers, politicians, yoga instructors, lawyers, baristas, doctors, and artists who live their lives and do their jobs while loving others as they want to be loved, turning the other cheek, giving without expecting repayment, and bringing justice and reconciliation to a world desperate for it.