It is said in the name of Rabbi Yitzchok Blauser: Trust in the Almighty is a very precious attribute. The Talmud (Sotah 48b) tells us that if a person has enough bread to eat today, he is lacking a degree of trust if he worries about what he will eat tomorrow.

Bear in mind, however, that this applies only to a person working on his own attributes. When it comes to other people, we must be concerned about what they will eat tomorrow... and for many days to come.