It is extremely important to guard carefully every word that comes out of your mouth. Your communication must be used to bless and not curse others.
Read: Ephesians 4:29
29 Do not let unwholesome [foul, profane, worthless, vulgar] words ever come out of your mouth, but only such speech as is good for building up others, according to the need and the occasion, so that it will be a blessing to those who hear [you speak].