Have you ever heard of winnowing? It is an ancient and simple process by which the wheat (good) is separated from the chaff (undesirable) by means of the wind.
A dictionary says regarding ‘winnow’: “To separate the wheat from the chaff by means of the wind. To get rid of undesirable components. To blow chaff off and away”.
The cut wheat with the chaff together, are tossed to the wind which blows away the lighter chaff, and allows the heavier wheat to fall to the ground, thus separating the good from the bad. Note that the goodness of the wheat, harder to see when commingled with the chaff, is now pure and stands out.
In like manner, GOD allows a “wind” to blow through His Church every now and then in order to separate the faithful from the unfaithful, the good fruit from the rotten fruit, the good fish from the bad fish, and the wheat from the chaff. The goodness of the faithful, now is much more apparent.
In the Old Testament the temple was cleansed of undesirables, 2Chron 29:16, as was the temple in the New Testament twice, and by Jesus Christ Himself, (2nd time) Matthew 21:12-13, Mark 11:15-17, Luke 19:45-48, (1st time) John 2:14-16.