MTS, FWIW I will pass along a paraphrase of something I read last night.
Worrying will divide the mind. It divides it into what needs to be dealt with today and what might happen in the future. God gives us just enough to deal with today. When tomorrow comes, He will give us just enough to deal with tomorrow. When you divide the mind by worrying, you take away from what God has given you to deal with today.