Think of what is above, not of what is on earth. (Colossians 3:2)
From time immemorial, man has conceived of three levels. 1) Here—the observable cosmos. 2) Up. 3) Down.
Here: the earth, the universe…day-by-day life with baseball games and back-to-school sales and train wrecks and summer movies. This level involves constant change, time passing, uncertainty, potential (that can be fulfilled or not), injustice lurking in every corner, fleeting pleasures, the possibility of a steak being good or bad, etc.
In other words, nothing on this level is sure, nothing absolutely permanent. Twinkies may or not be available in the future. It might rain tomorrow; it might not. This level has excitement. But Fate is fickle. It would be nice if the Redskins went to the playoffs this year. But they might not.
On the other hand, the other two levels—the upper and the lower—they are more stable. Their realities endure.