From the book Grow Rich While You Sleep
"It is not our problems which disturb us; it is our lack of faith in our ability to solve them."
Whether it's lack of faith or knowledge, God knows the answer and we can ask that it be shown to us. At the same time we need to quiet the worry of our mind and listen for the answer from our hearts.
Here's the affirmation from the book to do so:
"I am at peace with myself and the world. Problems facing me are no longer disturbing because I have made contact with my true source of intelligence and power. I am guided to do the right thing at the right time."