The wait in between
This is where resolve is actually tested, not in the effort, but in the silence after. When the work is done and the results haven't arrived, and there's nothing left to do but wait. Whispers of doubt shows up here but real progress rarely announces itself early.
The discipline was never in the effort. It's in staying steady when there's nothing yet to show for it. That's the part most people quit in.
There is no shortcut between what you gave and what's coming. There is only the wait and what it costs you to hold on without proof. Faith is what resolve becomes when sight runs out.