John 7:24 (NKJV)
The saying that "You can't judge a book by its cover" goes back over 100 years and it is an idiom that many people are familiar with. How something looks on the outside, or at first glance, may not be a true representation of what that thing is really like. This principle is true in many areas, including with people. When you first meet a person, you may form an opinion of them that later proves to be wrong. We know that it takes more than a few minutes to really get to know someone, but is there was way that we can get to know what someone is really like?
Some people say that we should not judge other people. In a way that is correct, but in another way it is not. While we do not have the right to condemn other people and judge them for their mistakes or things that we might think they have done wrong, we need to make a correct judgement about people as to who they really are. Jesus said in John 7:24 that we do not judge people or things by appearance, but we must make a righteous, a correct, judgment. We don't base our assessment of people on what we see outwardly, but we must focus on their actual character and what they have on the inside.
Jesus said in Matthew 12:34 that it is out of the abundance of the heart that the mouth speaks and in Mark 7:16 Jesus said we would know people by their fruits, by what is produced in their lives. We need to be wise and discerning with people and not be deceived by just one statement or action that is made. You can learn a lot about someone by listening to what they say and watching how they act over a period of time; this is how we can make a correct determination of that person and who they really are. God wants us to have good relationships with the right people and being able to correctly know who people are will help us make right choices in our relationships.