A future you hold as settled starts giving orders, and fear's orders deliver a person straight to the thing itself.
Whatever outcome a person treats as certain begins issuing instructions: which road, whose counsel to discount, what gets called safety. Sword and famine were already installed as the sure thing, and that certainty organized every decision underneath it, including the one that looked like escape.
God offered the same faculty a different object and asked them to be that sure of a promise instead of a blade. They kept the aim and changed only the address. What that costs is every ounce of planning and nerve a person has, spent on transport toward the feared thing rather than away from it.