Ephesians 4:29-30

Let no foul or polluting language, nor evil word nor unwholesome or worthless talk [ever] come out of your mouth, but only such [speech] as is good and beneficial to the spiritual progress of others, as is fitting to the need and the occasion, that it may be a blessing and give grace (God's favor) to those who hear it. And do not grieve the Holy Spirit of God [do not offend or vex or sadden Him], by Whom you were sealed (marked, branded as God's own, secured) for the day of redemption (of final deliverance through Christ from evil and the consequences of sin).