If anyone thinks he is religious and does not bridle his tongue but deceives his heart, this person's religion is worthless. - James 1:26
Do not speak evil against one another, brothers. The one who speaks against a brother or judges his brother, speaks evil against the law and judges the law. But if you judge the law, you are not a doer of the law but a judge. There is only one lawgiver and judge, he who is able to save and to destroy. But who are you to judge your neighbor? - James 4: 11-12
Whoever belittles his neighbor lacks sense, but a man of understanding remains silent. - Proverbs 11:12
Let all bitterness and wrath and anger and clamor and slander be put away from you, along with all malice. Be kind to one another, tenderhearted, forgiving one another, as God in Christ forgave you. - Ephesians 4:31-32