It is certainly the case that when a farmer sows wheat, he may expect to harvest wheat, and not carrots. When it comes to farming, like produces like, and it would be a poor and quickly disappointed farmer who operated according to any other principle.
And it is equally true that the size of a farmer’s fall harvest will depend on the amount of seed sown in the spring. Sow sparingly, reap a modest harvest; sow generously, reap in abundance. Slightly different from the first, but still an application of the general principle of like producing like.
These rustic illustrations of a general principle are often carried into the realm of religion. Sometimes their use in that realm is quite coarse, as when they are employed in appeals to donate generously to one’s church. In other cases, it finds application in giving religious sanction to an almost universal human appreciation of ‘aptness’ in punishment.
But do these applications about financial generosity being rewarded in kind, or criminal behavior meriting an equivalent response, really get at the heart of what Jesus is teaching when, in many different images, he points to a relationship of correspondence between our behavior and the consequences of our behavior? (Luke 6:38; Mark 4:24; Matthew 7:12; and elsewhere.)
As for the first, the whole tenor of Christ’s teaching is to the point that following Him will not result in worldly reward. The rich young ruler is to dispose of his wealth, not with the expectation of a larger fortune, but because it is a hindrance to following Christ. Do what I tell you, He teaches his disciples, and the world will hate you. And so on. It is consistently Christ’s emphasis that one must not seek or expect worldly reward for one’s activities on His behalf, that such motivation in fact diminishes their spiritual weight. And to respond that the monetary reward will take place beyond the Pearly Gate is descending into inanity.
As for the moral application of the principle, suffice it to say that Jesus explicitly rejects it: You have heard it said, Eye for eye…but I tell you… Whatever sort of case – moral or prudential – can be made for equality or correspondence of punishment to infraction, it cannot find its warrant in the thought of Christ.
Which only brings us to our real interest. How then are we to understand good measures pressed down and running over, bearing fruit a hundredfold, and all the rest of Christ’s imagery?