Believing is seeing: seeing G-d's presence in the world, in sickness and in health, (the opening verses of Vayera), this week's Torah reading.
We must see His presence in the good and the bad, (the destruction of Sodom), and even when He seems to place an impossible task before us, (the binding of Isaac, Yitzchak).
Abraham's open-eyed faith in G-d led him to Mount Moriah, the place of the future Holy Temple, the place Abraham named "'Hashem will see,' as it is said to this day: On the mountain, 'Hashem will be seen.'" (Genesis 22:14).