I believe that the single Bible verse most taken out of its context in Matthew 7:1:

Judge not that you be not judged.

Often a person will employ this verse to defend sinful behavior, but such is not the meaning at all.  The Bible actually encourages us to look at the behavior of others.

As for a person who stirs up division, after warning him once and then twice, have nothing more to do with him – Titus 3:10

Thus you will recognize them by their fruits. Matthew 7:20 (Speaking of false prophets)

Remember your leaders who have spoken God’s word to you. As you carefully observe the outcome of their lives, imitate their faith. – Hebrews 13:7

If anyone sees his brother committing a sin that does not bring death, he should ask, and God will give life to him… 1 John 5:16a

We are not judging when we measure our life and the lives of others against the plain teaching of Scripture.  Judging occurs rather when we make value judgments and assume that we know the heart and motives behind the actions of others.  We are encouraged to observe the behavior of others but we must NEVER assume to know their heart.

In addition, this verse is part of a larger passage of Scripture (Matthew 7:1-5) that encourages us to examine our own hearts before judging the hearts of others.  We must not overlook the Biblical admonition to remove the foul motives of our own hearts.  When we do, we more accurately see the hearts of others.  In fact, when we remove our own foul motives (the beam) we recognize that the motives of others were nobler than we imagined (only a speck).

So the true applications of these verses would include

1. Don’t be so quit to assume to know the heart of others, and
2. Be careful to examine your own heart.