Ephesians 4:31 Let all bitterness, and wrath, and anger, and clamour, and evil speaking, be put away from you, with all malice:
Bitterness is the root of all the rest mentioned in above verse.
Bitterness is the unresolved violation of your justice system.
Unkind words, unjust actions, unexpected loss, unfulfilled expectations,
The results of bitterness--defiles you and defiles others.
Defiles your access-with men vs. 14, which blocks your relationship with God. 1 Cor, 13...take the examples of love, look at opposites and it describes bitterness.
Defiles your attitude, defiles your appetite.
Hebrews 12:14-15 [14] Follow peace with all men, and holiness, without which no man shall see the Lord: [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;