Grain must be ground to make bread; so one does not go on threshing it forever. Though he drives the wheels of his threshing cart over it, his horses do not grind it (Isaiah 28:28 NIV).
Bread is the final product we get after a lot of processes. And from this process that God has given man wisdom to learn we can understand much about spiritual discipline. Threshing is the process through which grain is beaten out from its husk. Thus the grain and chaff are separated. But this process is not continued beyond a reasonable point. It is stopped when the grain is ready for the next step.
Grain retains its shape though the process was unpleasant. But soon it will be ground to make bread. It is a much painful process. Then grain will lose its shape and will be broken to pieces and finally to real powder. It is at this point of time when it becomes flour that it becomes ready to make bread. It is only in such a condition that it can bring nourishment and health to the one who eats of it.
The lesson to be learnt is simple yet full of depth. God knows when to thresh us and remove the impurities that cover us. But He does not go on doing it forever. Then He puts us through deeper tests to grind us to be useful to others. But again the horses do not grind it, but only the wheels of the threshing cart are used. This means that God also knows what form of discipline is to be used to make us ready for the Master’s use. It also means that He will not use undue pressure to break us down. There is a time and method for every discipline from God. Therefore we can take heart when we are threshed and ground for God’s business. Someday He will make this fine work complete. Then it will be perfect for its use.