What a better way to tell... People who seldom read the bible are quick to quote Matthew 7:1 when they want to silence someone whose opinion they don't like. "Judge not, that you be not judged" seems like the perfect response.
In context, however, the passage indicates that we are indeed to judge; we're just supposed to avoid faulty judgments. Furthermore, our judgments are to begin with self: "First remove the plank from your own eye, and then you will see clearly to remove the speck from your brother's eye," Jesus said. (v.5) We need to discern truth from falsehood.
Jesus used the metaphor of fruit to give us the proper criteria for judging. " By their fruits you will know them." (v.20) We are to judge people (including ourselves) by the quality of the fruit they produce. This fruit can't be judged by earthly values such as how good we look (v.15) It must be judged by heavenly values - the fruit of the Spirit produced within us - love, joy, and peace (gal.5:22).
Our tendency is to judge by appearance. But God judges by what we produce, and so should we.
Therefore....Be slow to judge others and quick to judge yourself.