The farmer has regard to the nature of the seed as well as its value and adapts his threshing technique accordingly. To treat each seed alike would irreparably damage some or leave others unseparated from the husk. He must apply exactly the correct length of time to achieve the end in view. Gentle tapping with a rod is sufficient for the dill but the wheat requires the tribulum, a heavy threshing-sledge. His intelligence and experience prevents the farmer from excess in his threshing method. As soon as the seed is separated from the restricting husk, the threshing process ceases. (p. 40)Here we see that the trials God allows for each believer may be distinct, specific to the individual. God can be trusted to not give us more than we can bear, or, to continue Sanders' analogy, to not crush the kernel of wheat or the dill in this process, but to apply what is necessary for our growth in Christ.
One of the questions I have been considering recently follows on this topic. Considering again the role of suffering in the Christian life, to what extent are we to seek out suffering--rather than simply accepting the suffering that God grants us? Or perhaps, if we simply walk in obedience, will the necessary suffering come through that?
We live in a culture in which we expend a wealth of energy and resources to escape from and alleviate suffering and discomfort. To what extent might we be trying to escape at all costs the very thing that God is using for our growth in Him?