“For he that will love life, and see good days, let him refrain his tongue from evil, and his lips that they speak no guile:”  
1Peter 3:10

He tells you plainly what you need to do to live the best life the best way possible in love. He tells you what you should do to ensure you only see good days.
He says refrain your tongue from evil. This means your tongue is a tool given to you by God to control your experiences in life and even more specific, your tongue is that control tool that will guide the outcome of your days- Monday, Tuesday… …Sunday!
You don’t want to see and be stuck in a life filled with evil? Don’t speak evil. You don’t want to the ‘pendulic’ good day, evil day motion of the human life? He says don’t speak evil- even as a joke!
No ‘you are not dead’ because someone said something funny and that is the popular response to really funny jokes.
No ‘the Government will not kill you in this country’ because that’s how people tend to respond to hardship.
No, you are not ‘mad’ neither are you a ‘bad guy’.
It is the word of God that unveils to you the full consequences of your actions, now he tells you without mincing words: simple, clumsy and/or careless statements would ruin your day and also ruin your life!