The parable about the wheat and the chaff or weeds is a good reminder about how the Gospel of Christ requires us to trust more in the work of God than in our own judgment. The weeds and the wheat do not correspond to different individuals as much as they refer to the mixed nature of our inner life. In the soul of any man or woman you will find both weeds and wheat – both what is obviously good and what is obviously bad. There is a temptation by the disciples of Christ, by those in a position to work the field, to get rid of the weeds. Obviously weeds are the bad thoughts, actions, words, etc., that are discernable at any given time. The question is not whether or not they need to be gotten rid of, but when they need to be gotten rid of. There are some faults – even moral faults – that we may find in ourselves or in others which actually play a role in preventing something worse. These weeds end up protecting the wheat. A great example of this is any humiliating sin. God may indeed allow a humiliating sin so that the wheat of humility will not be removed. Pride is a worse sin than anything we could do that would humiliate us.
Jesus gives us fairly straightforward criteria for discerning good and evil. Many times, when what is evil takes the form of dogs or pigs we can recognize it a mile away. Capital sins are supposed to be of that sort: murder, fornication, deception, etc. Sometimes evil takes the appearance of sheep though. They are wolves hiding in sheep’s clothing when what they say delights or entices but leads to sin. This is the most pernicious attack of the enemy, because we are in some ways fooled and consent to evil while we were unable to grasp the necessary relationship between what seems to be good and its evil consequences. We see this in gossip: sometimes what starts as simply giving people updates turns into complaining about others, or spreading rumors about what others have said or done. We see it in murder: sometimes what starts as taking a stand against apparent injustice ends in the death of another. We see it in fornication: what starts as pleasant affection ends in the act reserved for marriage. We see it in greed: what starts as working to have enough turns into getting as much as possible by any means necessary. The key to identifying the wolf is trying to see where what seems to be good actually leads.