The Phrase
"The wheat and the tares" - good and evil coexisting within the same community, requiring patient tolerance until the final judgment separates them. Jesus's Parable of the Wheat and Tares (Matthew 13:24-30, 36-43) gave English an image and phrase for the necessity of tolerating evil rather than attempting to eradicate it prematurely.
Biblical Origin
The parable describes a man who sows good wheat seed, only to have an enemy sow zizanion - darnel, a weed so similar to wheat in its early growth that it cannot be distinguished until the grain appears. The servants ask if they should pull out the weeds; the master replies: "No, because while you are pulling the weeds, you may uproot the wheat with them. Let both grow together until the harvest."
Jesus interprets the parable in Matthew 13:36-43: the sower is the Son of Man; the field is the world; the good seed are the children of the kingdom; the weeds are the children of the evil one; the harvest is the end of the age; the harvesters are angels. The logic is eschatological patience: human judgment is insufficiently precise to separate the truly righteous from the apparently righteous; only divine judgment at the end of history can do this without error.
Semantic Drift
"The wheat and the tares" entered English as an expression for the necessary coexistence of good and bad - particularly within institutions that cannot be purged without damaging what they contain. The phrase is invoked in discussions of institutional reform, political strategy, and religious discipline. Its specific warning is against premature purging: the attempt to achieve a pure community by expelling all suspect members may destroy more than it saves.
This warning has been applied in discussions of the Reformation (should one reform the Church from within or separate from it?), of political parties (should moderates remain in a party radicalizing around them?), and of civic institutions (should good people leave corrupt organizations or work to improve them from within?). The parable's practical wisdom - that roots are entangled, that visible difference is not always real difference, that judgment requires more information than participants possess - translates directly to these dilemmas.
Cultural Presence
The phrase appears in Augustine's ecclesiology (his argument against the Donatists rested partly on the Parable of the Wheat and Tares), in Luther's early writings on church discipline, and in contemporary discussions of pluralism and tolerance. Its continued relevance reflects the perennial character of the dilemma it addresses: how to maintain community standards without destroying the community in the process of enforcing them.