We see ourselves reflected in the lives of others. The christian is to judge, contrary to popular false teachings, 1 Corinthians 2:15 But he that is spiritual judgeth all things, yet he himself is judged of no man. However, he is not to judge hypocritically. Thats the context of Matthew 7. Matthew 7:1 Judge not, that ye be not judged. Matthew 7:5 Thou hypocrite, first cast out the beam out of thine own eye; and then shalt thou see clearly to cast out the mote out of thy brother's eye. Lots of times the temptation is to say things about others like, " I don't like them," or " they are arrogant," or " he has an attitude," when what you are doing is seeing yourself reflected in the life of someone else and you don't like it. You are able to notice the faults in others because you do them yourself, Romans 2:1 Therefore thou art inexcusable, O man, whosoever thou art that judgest: for wherein thou judgest another, thou condemnest thyself; for thou that judgest doest the same things.

There is also a temptation to get mad everytime you hear someone say something about you that you dont like. Look at what the Bible says about that. Ec 7:21 Also take no heed unto all words that are spoken; lest thou hear thy servant curse thee:
Ec 7:22 For oftentimes also thine own heart knoweth that thou thyself likewise hast cursed others. Sometimes you get mad at the way others talk and you do the same thing and you don't like it. As in water face answereth to face, so the heart of man to man. Maybe your heart is seeing it's own reflection and you are looking in a mirror not liking what you see. Learn from it and look in God's mirror that is an accurate reflection, James 1:25 But whoso looketh into the perfect law of liberty, and continueth therein, he being not a forgetful hearer, but a doer of the work, this man shall be blessed in his deed. God's word is like water (Eph 5:26) and you can look at your reflecton in that mirror and see the face of Jesus Christ (Jn 1:1) and the man Christ Jesus (1 Tim 2:5) will show you the changes that need to be made to your heart and how to make them.