Jesus does not say, Blessed is the one who does not think about anything–that person is a fool. He says be carefully careless about everything save one thing–your relationship to God. That means we have to be studiously careful that we are careless about how we stand to self-interest, to food, to clothes, for the one reason only: that we are set on minding our relationship to God…

Do not make the ruling factor of your life what you shall eat, or what you shall drink, but make zealous concentration on God the one point of your life.

Matthew 6:33-34