Ephesians 4:31-32 KJV

31 Let all bitterness, and wrath, and anger, and clamour, and evil speaking, be put away from you, with all malice:
32 And be ye kind one to another, tenderhearted, forgiving one another, even as God for Christ's sake hath forgiven you.

James 3:15-17 KJV

15 This wisdom descendeth not from above, but is earthly, sensual, devilish.
16 For where envying and strife is, there is confusion and every evil work.
17 But the wisdom that is from above is first pure, then peaceable, gentle, and easy to be intreated, full of mercy and good fruits, without partiality, and without hypocrisy.

Hebrews 12:15 KJV

15 Looking diligently lest any man fail of the grace of God; lest any root of bitterness springing up trouble you, and thereby many be defiled;