Mt 13:27 So the servants of the owner came and said to him, 'Sir, did you not sow good seed in your field? How then does it have tares?'
28 "He said to them, 'An enemy has done this.' The servants said to him, 'Do you want us then to go and gather them up?'
29 "But he said, 'No, lest while you gather up the tares you also uproot the wheat with them.
In other parables, servants are the ones sent to gather guests for the wedding feast. In other words, servants are soul-winners in the parables. It is often taught that we can't be sure who the tares are, but the servants knew; they even offered to get rid of the tares.
But the owner explained (in the Greek) that the roots of the tares and the wheat are so intertwined that if they started pulling up the tares, they would pull up wheat with them.
Which brings up the question: How did the servants recognize the tares? Why didn't the pastors, or the bishops, or the elders, or the teachers recognize the tares? What did the soul-winners see that the others didn't see?