Both of today's Mass readings conspire to tell me to take life one day at a time. The first reading, from Proverbs, includes this daring prayer: "Give me neither poverty nor riches, provide me only with the food I need." Then in the Gospel, Jesus sends the Twelve off and gives them only "power and authority," while forbidding them to take their own provisions. If I understand correctly, the Jesuits still send their young members at one point in their formation out the door for several weeks with only enough money for a single day's needs. Some of them have written about the surprising experiences of God's providence that this opened them to.
Maybe that's the point. Maybe God put things like this in the Bible (along with "consider the lilies of the field"; "give us this day our daily bread") because he wants to opportunity to reveal himself as a caring Provider of all our needs. When we are busy providing for ourselves, as Proverbs hints, we may see everything that comes our way as our just desserts, in which God is only a marginal player (or maybe just a distant observer). Making the effort to be content with our "daily" bread keeps us from getting entrenched in the search for security. It leaves us free to be sent, like the Twelve in today's Gospel.