Why might our judgment be out of proportion? One reason is that we can never know all of the facts or the whole person. Humanly, our experience, oversight, and understanding are limited. We must learn to avoid making the kinds of judgments spectators make at sporting events. A fan may be a hundred yards from the playing field, but he will make a judgment as if he were in a perfect position to see every detail of a given play. He feels perfectly justified to criticize the umpire, referee, or player who was right on the spot and involved in the heat of the action.
We never see the whole picture as God does. It is very difficult to know a person's intentions or his strengths and weaknesses. We may have a very unfavorable impression of a person because we saw him perform in his weakest area. Yet, this same person may have unseen strengths in other areas. Each of us is a "mixed bag," and only God has the oversight, insight, experience, wisdom, and love to make a completely fair judgment.
A second and overlapping reason is that it is almost impossible for us to make an impartial judgment. As a result of our experiences, we have built-in biases that color our judgment. John 8:12-16 shows that the Pharisees misjudged Jesus because they had many of the same limitations we do. They judged "according to the flesh," that is, as others have translated this phrase, "by material standards" (Goodspeed), "by the outside" (Moffatt), "after your earthly fashion" (Knox). But even Jesus, though He was qualified to do so (verse 16), says that He was not judging anyone (verse 15). He imposed the same limitation on Himself that He imposes on His followers in Matthew 7:1!