The Parable of the Wheat and the Weeds.

He presented another parable to them: “The kingdom of heaven may be compared to a man who sowed good seed in his field. But while people were sleeping, his enemy came, sowed weeds among the wheat, and left. When the plants sprouted and produced grain, then the weeds also appeared. The landowner’s slaves came to him and said, ‘Master, didn’t you sow good seed in your field? Then where did the weeds come from?’
“ ‘An enemy did this!’ he told them.
“ ‘So, do you want us to go and gather them up?’ the slaves asked him.
“ ‘No,’ he said. ‘When you gather up the weeds, you might also uproot the wheat with them. Let both grow together until the harvest. At harvest time I’ll tell the reapers: Gather the weeds first and tie them in bundles to burn them, but store the wheat in my barn.’”-Mathew 13:24-30