The following is written by Ray Ortlund:

Q: What are the duties required in the ninth commandment?

A: The duties required in the ninth commandment are the preserving and promoting of truth between man and man and the good name of our neighbor, . . . loving, desiring and rejoicing in their good name; . . . a ready receiving of a good report and unwillingness to admit of an evil report concerning them.

So says the Westminster Larger Catechism. The Bible itself is so clear against gossip, probably because we are so inclined toward gossip:

O Lord, who shall sojourn in your tent?
Who shall dwell on your holy hill?
He who does not take up a reproach against his friend. Psalm 15:1, 3

There are six things that the Lord hates,
seven that are an abomination to him: . . .
one who sows discord among brothers. Proverbs 6:16, 19

Thou shalt not go up and down as a talebearer among thy people. Leviticus 19:16, AV

Do not speak evil against one another, brothers. James 4:11

Argue your case with your neighbor himself,
and do not reveal another’s secret. Proverbs 25:9

God gave them up to a debased mind . . . . They are gossips. Romans 1:28-29

There are many biblical passages confronting gossip. The witness of God against this sin is overwhelming.

What is gossip? It is not necessarily false information. Slander is false. Gossip might include true information, and maybe that’s why gossip doesn’t always feel sinful. What makes it sin is, first and foremost, that God says it’s sin. But gossip spreads what can include accurate information to diminish another person. That is not how people behave when they are living in the power of the grace of God.

Gossip is our dark moral fervor eagerly seeking gratification. Gossip makes us feel important and needed as we declare our judgments. It makes us feel included to know the inside scoop. It makes us feel powerful to cut someone else down to size, especially someone we are jealous of. It makes us feel righteous, even responsible, to pronounce someone else guilty. Gossip can feel good in multiple ways. But it is of the flesh, not of the Spirit.

Adultery too is a serious sin, and one likely to be disciplined in a church. But I have never seen a church split over the sin of adultery. Gossip is a sin rarely disciplined but often more socially destructive than the sensational sins.

Gossip leaves a wide trail of devastation wherever and however it goes – word of mouth, email, blogging, YouTube. It erodes trust and destroys morale. It creates a social environment of suspicion where everyone must wonder what is being said behind their backs and whether appearances of friendship are sincere. It ruins hard-won reputations with cowardly but effective weapons of misrepresentation. It manipulates people into taking sides when no such action is necessary or beneficial. It unleashes the dark powers of psychological transference, doing violence to the gossiper, to the one receiving the gossip and to the person being spoken against. It makes the Body of Christ look like the Body of Antichrist – destroyers rather than healers. It exhausts the energies we would otherwise devote to positive witness. It robs our Lord of the Church he deserves. It exposes the hostility in our hearts and discredits the gospel in the eyes of the world. Then we wonder why we don’t see more conversions, why “the ground is so hard.”

What should we do when a conversation starts slipping into gossip? We should immediately challenge the sin: “Hey friend, sorry to interrupt, but this is gossip. So here’s the deal. This conversation is now on hold until you go get _____________, and then you can start over and say whatever you feel you must say right to his face. I am willing to be a witness to that conversation, but I will not participate in gossip. What do you choose to do?” Amy Carmichael established this rule at her mission station: “Never about, always to.”

“Let all things be done for building up” (1 Corinthians 14:26). Therefore, let’s always ask ourselves, “These words about to rise up out of my mouth or go out through my keyboard – do they build up? Am I being constructive? If the person I feel like discussing were here with me right now, how would his presence change what I feel like saying?”

“Do not be deceived: . . . revilers will not inherit the kingdom of God. And such were some of you. But you were washed, you were sanctified, you were justified in the name of the Lord Jesus Christ and by the Spirit of our God.” 1 Corinthians 6:9-11