Anger: Being Your Brother’s Keeper
Cain and Abel
4:1 Now Adam knew Eve his wife, and she conceived and bore Cain, saying, “I have gotten  a man with the help of the Lord.” 2 And again, she bore his brother Abel. Now Abel was a keeper of sheep, and Cain a worker of the ground. 3 In the course of time Cain brought to the Lord an offering of the fruit of the ground, 4 and Abel also brought of the firstborn of his flock and of their fat portions. And the Lord had regard for Abel and his offering, 5 but for Cain and his offering he had no regard. So Cain was very angry, and his face fell. 6 The Lord said to Cain, “Why are you angry, and why has your face fallen? 7 If you do well, will you not be accepted?  And if you do not do well, sin is crouching at the door. Its desire is for  you, but you must rule over it.”
8 Cain spoke to Abel his brother.  And when they were in the field, Cain rose up against his brother Abel and killed him.
21 “You have heard that it was said to those of old, ‘You shall not murder; and whoever murders will be liable to judgment.’ 22 But I say to you that everyone who is angry with his brother  will be liable to judgment; whoever insults  his brother will be liable to the council; and whoever says, ‘You fool!’ will be liable to the hell  of fire. 23 So if you are offering your gift at the altar and there remember that your brother has something against you, 24 leave your gift there before the altar and go. First be reconciled to your brother, and then come and offer your gift.
26 Be angry and do not sin; do not let the sun go down on your anger, 27 and give no opportunity to the devil.
31 Let all bitterness and wrath and anger and clamor and slander be put away from you, along with all malice. 32 Be kind to one another, tenderhearted, forgiving one another, as God in Christ forgave you. (ESV)
 4:1 Cain sounds like the Hebrew for gotten
 4:7 Hebrew will there not be a lifting up [of your face]?
 4:7 Or against
 4:8 Hebrew; Samaritan, Septuagint, Syriac, Vulgate add Let us go out to the field
 5:22 Some manuscripts insert without cause
 5:22 Greek says Raca to (a term of abuse)
 5:22 Greek Gehenna; also verses 29, 30