Because of this I say to you, do not worry about your life, what you should eat or what you should drink; nor your body, what you should put on. Is not life more than food, and the body more than clothing? Look at the birds of the air. They do not sow nor do they reap, nor do they gather into barns, and your Heavenly Father feeds them. Are you not much more valuable than they? And who of you by worrying is able to add one cubit to his stature?
And why do you worry about clothing? Consider carefully how the lilies of the field grow: They do not labor nor do they spin. Yet I say to you that not even Solomon in all his glory was adorned like one of these. But if God thus clothes the grass of the field, existing today and tomorrow being thrown into the furnace, will He not much more clothe you, O you of little faith?
Therefore do not be anxious, saying, ‘What shall we eat?’ Or ‘What shall we drink?’ Or ‘What shall we wear?’ For the Gentiles seek after all these things. For your Heavenly Father knows that you have need of them all. But seek first the kingdom of God and His righteousness, and all these things will be added unto you.
Therefore do not worry about tomorrow, for tomorrow will worry about itself. Sufficient to the day is its own trouble.
From Jesus’ Sermon on the Mount, Matthew 6:25-34.
Why should we worry when our Lord himself has assured us of God’s care!