Writing to a friend regarding the adage that "His grace is sufficient":
We have an insufficient understanding of the term "sufficient." Because the common usage has come to mean "just barely enough to cover it," we tend to look at "His grace is sufficient" as a kind of wary half-promise.
But the real meaning of "His grace is sufficient," says nothing about the amount of it nor its efficacy. What it says is that it is His grace alone--entirely and only. His grace is sufficient in that nothing need be added to it and we only need a kind of meta-desire for it to be effective. We need to want to want to want to want to cooperate, and His grace makes it possible step by step.
