Bitterness as Idolatry
Helpful quote from the ESV Study Bible on Hebrews 12:15. The author warns against “bitterness” by alluding to Deut. 29:18, which describes one who turns away from God and pursues other gods. A bitter and resentful person is like a contagious poison, spreading his resentment to others. Oh, God, may we never be such a poison to others.