Reference

Ephesians 4:30, 31; Hebrews 12:5

If we are not diligent in rooting out bitterness (Heb 12:5a), it will grow and bear fruits of corruption (Galatians 6:8) causing trouble among the brethren (Heb 12:5b). Therefore, bitterness hurts not only the one who is bitter, but those around you as well.  We must call out bitterness for what it is, a sin from Satan (James 3:14, 15) and call upon the Lord for strength that we may forgive (Ephesians 4:31; I John 1:9) and so that we may be forgiven.