Become the master of your tongue. According to the Maharal, what is sick is that he can't keep a secret. He sees someone do something wrong, and he can't keep it to himself. A person who has no vessels to keep a secret is not a whole human being. The holiness is that a human has a body which shows and a soul which is secret.
Life depends on the secret of the soul being in the body.
That is the essence of human life. G-d, who is not showing. Someone who can't keep a secret cuts himself off from his soul, cuts himself off from G-d. The more real something is, the less you can prove it and the less you can see it. The more real something is, the more important it is to you.