Cain and Abel (Genesis 4)
Antediluvian Age Begins - Fall to the Flood
Anticipating the fulfillment of the Promise God made in (3:15), Eve exclaims, "I have gotten a man from the Lord" (4:1) The birth of Abel in (4:2) illustrates the 4th of 4 methods God has chosen to bring human beings into this world.  Adam - born without father or mother,  Eve - born without a mother,  Christ - born without a father,  All others - born with father and mother.
Sin, which seemed small in its beginning in the garden, soon began to develop and manifest its real enormity. The story of Cain and Abel, which illustrates this growth of sin, outlines itself in four words:
Whether moved simply by a sense of sin or actuated by an unrecorded command of Jehovah, Cain and Abel brought offerings and presented them before the Lord.
 Cain's bloodless, cursed (3:17) offering rejected (4:5),  "Without the shedding of blood there is no remission" Lev. 17:11; Heb 9:22),  Abel offers a lamb and is accepted (4:4),  Dr. Barnhouse "The highway to the cross was not firmly established. Here the first lamb is seen, one lamb for one man. Later at Passover, 1 lamb for one household (Ex 12), then on the day of atonement, there will be one sacrifice for the nation (Lev 16), Finally it is Christ who takes away the sin of the world (Jn 1:29)
Because his own offering was rejected while that of his brother was accepted, Cain was moved to jealous rage and rose against Abel his brother, and slew him. Cain becomes the first murderer (4:8) and the First liar (4:9) This fratricide is apparently recorded to illustrate and enforce the depth and depravity of sin, and to emphasize the need for the redemption, whose promise and outlines began to appear even in the book of Genesis.
To show his abhorrence, Jehovah pronounced a curse upon the murderer; "And now art thou cursed from the earth, which hath opened her mouth to receive thy brother's blood from thy hand."
"A fugitive and a vagabond shalt thou be in the earth."
 Cain was driven from the blessings of God;  Marries one of his sisters (4:17; 5:4)  Dwells in the land of Nod.
* Cain builds the first city and names it Enoch (after his own son) which means "dedication." This urban project was no doubt an attempt to counteract God's curse in 4:12.
* Lamech, Cain's great-great-great-grandson becomes the first recorded polygamist (4:19), the first recorded songwriter (the word "speech" in 4:23 may refer to a poem or ballad), the second recorded murderer (4:23)
* Jabal becomes the inventor of the tent and developer of the Nomadic life style. He also devised formal systems for domesticating and commercially producing animals apart from sheep. His name means "wanderer" (4:20)
* Jubal becomes the inventor of both stringed and wind musical instruments. His name means "sound" (4:21).
* Tubal-Cain becomes the inventor of metallurgy both in bronze and iron (4:22)