No one can serve two masters, for either he will hate the one and love the other,
or he will be devoted to the one and despise the other. You cannot serve God and money.
Therefore I tell you, do not be anxious about your life, what you will eat
or what you will drink, nor about your body, what you will put on.
Is not life more than food, and the body more than clothing?  
– Matthew 6:24-25

In answer to Jesus’ question: Of course life is more than food and clothing.  But if you make your life about food or clothing or money or any number of other things, you have made that thing into an idol.  It has become your god.  It has become your master whom you serve.  And your idol will make you anxious.  Why?  Because your idol can be threatened.  If you treasure anything on this earth, it can be lost (see v19).  And when your idol (what is central to you) is threatened or lost, you will become anxious.  You will worry.

How different if we make our life all about God.  He cannot be threatened or lost.  If our lives are about him, we need not worry.

Next time you catch yourself worrying, ask yourself: what idol in my life is being threatened?  Then repent of your anxious idolatry and turn back to the one true God.