David Powlison talks about not worrying from Luke 12. Here a short excerpt:
Then He lists reason after reason after reason why you should not be in the grip of fear and worry. He first says, “Consider the ravens.” Remember, Jesus is talking outside. He’s not utilizing a literary device or a sermon illustration He thought up in his study! He’s out in the open in Palestine. They have crows there, just like here in Glenside, Pennsylvania. Their kind of crow happens to be the gray-hooded crow. Those crows are flying around overhead cawing, or hopping around on the ground squabbling. “Take a look at those crows! Think about them. They neither sow nor reap. They don’t have storerooms or barns. They make no preparations and have no storage. Yet God feeds them. How much more valuable are you than birds?”
Read the first part of the series here: Don’t Worry | CCEF.