Christ’s admonition that we not worry about tomorrow; for tomorrow will take care of itself seems, perhaps, a little irresponsible if not impossible to carry out. However, I believe that Jesus is impressing upon us the fact that anxiety about tomorrow and the days thereafter can obscure God’s presence and grace given in the present moment—given to deal with the actual challenge at hand and not one that may or may not occur in the future. Grace and strength are given at time of need and not before. Recalling how God’s grace has met us in our past needs can serve to bolster our trust in his faithfulness and dependability. Mary’s fiat—let it be done to me as you have said—is just such an instance of this trust and letting go of worry about tomorrow. We would do well to imitate her!