Romans 8:28, NIV: And we know that in all things God works for the good of those who love him, who have been called according to his purpose.

Consider King David. When he faced Goliath, do you think he was an optimist--a glass-half-full sort of person? Or was he a glass-half-empty pessimistic sort? It seems to me he was neither. In David’s familiar Psalm we read, “Thou preparest a table before me in the presence of mine enemies: thou anointest my head with oil; my cup runneth over” (23:5). When David faced the giant, he undoubtedly took inventory of his resources. With David’s size and what he had in hand, most of us may have quickly assessed the glass half-full--or less. But David did not consider only what was in his hand, but also Who he knew in his heart. As David factored God into the equation, the glass was not half-empty or half-full, but overflowing.
We so very often approach decisions and situations with our measuring cup in hand; limiting ourselves to what we have and what we can do. But with God, all things are possible indeed. There is no measuring cup that can contain His resources. And there is no limit to the mountains He can move through those, who when trusting Him, clearly see the glass as overflowing.