What is “the field” in Jesus’ parable of the wheat and the tares? Matthew 13:24 seems to refer to the church, but verse 38 says it is the world.
In my opinion, the design of the parable is simply this: So long as the pilgrimage of the Church in this world continues, bad men and hypocrites will mingle in it with those who are good and upright, that the children of God may be armed with patience and, in the midst of offenses which are fitted to disturb them, may preserve unbroken stedfastness of faith.
It is an appropriate comparison, when the Lord calls the Church his field, for believers are the seed of it; and though Christ afterwards adds that the field is the world, yet he undoubtedly intended to apply this designation, in a peculiar manner, to the Church, about which he had commenced the discourse.
But as he was about to drive his plough through every country of the world, so as to cultivate fields, and scatter the seed of life, throughout the whole world, he has employed a synecdoche, to make the world denote what more strictly belonged only to a part of it.
Answered by John Calvin (1509-1564)