From 7 Myths About Singless by Sam Alberry, pg.138-139:
"I am grateful to my friend Kathy Keller for reminding me that God doesn't give us hypothetical grace but only actual grace. The point is that when we imagine all those worst-case-scenarios, we are imagining them without factoring in the presence and grace of God that would be there if they actually happened. As Kathy wrote in an email once, "God doesn't play that game. He doesn't inject hypothetical grace into your hypothetical nightmare situation so that you would know what it would actually feel like if you ever did end up in that situation." He only gives grace for our actual situation. Replaying these scenarios over and over inner mind is therefore not at all helpful and actually factors out what God would be doing were it to ever happen. What we're imagining is actually life in that situation without God's presence. Better to find something else to fill our minds with. C.S. Lewis makes a similar point when he says, "Remember one is given the strength to bear what happens, but not the 101 different things that might happen." One of the Scriptures I found myself returning to during that time of meltdown, and which is still a wonderful comfort, is Psalm 139 and these well-known words:
Psalm 139:1-6
O Lord, you have searched me and known me!
You know when I sit down and when I rise up;
you discern my thoughts from afar.
You search out my path and my lying down
and are acquainted with all my ways.
Even before a word is on my tongue,
behold, O Lord, you know it altogether.
You hem me in, behind and before,
and lay your hand upon me.
Such knowledge is too wonderful for me;
it is high; I cannot attain it.