Jesus is the undisputed King of the world, who in this age of grace, reigns at the right hand of God the Father, and one day will return to reign on earth.  God always had a plan to be with His people and, though God was faithful in His covenants, the people fell short of faithfulness.  Sin has always been pervasive.  So, Jesus came on a rescue mission to earth, to die for the sins of mankind, of all who would repent and trust in Christ as their Savior, to save us from death, and, as He resurrected, so too would his children be resurrected after they die on this earth.  Because God is the author and sustainer and keeper of life and death.  He holds the keys and He fully reigns in power over all things.  There is only One God and One Way, and His name is Jesus Christ (John 14:6).

In the wake of the genealogy of faith of Chapter 5, the world takes a hard turn in opposition to God's authority and pursues everything else.  God stands and sees, the Judge of all the world, and watches as the world's culture has lost all sense of faith and morality.  And God expresses Himself so openly to us who read His Word today - that "the Lord was sorry that He had made man on the earth" (6:6).  This objectionable pursuit of sin by the world will not go unpunished, and God makes very clear what He will do - because justice requires action.  And God, as The Judge, will bring it.  But, in all the wickedness, there is one chosen by God, who walks with God, and his name is Noah. 

From the family line of Adam, there is both the fallout from tragedy (4:8) and a split of trajectories (4:25-26).  God's plan and the family line of His people will be carried, not by the firstborn or second born, but by the third son, Seth.  And God is faithful in continuing the line of His people, from Adam to Noah.  Enoch is of particular example, because of his righteous walk with God, God did something miraculous.  Many lessons in this passage for us to exemplify God's love, to seek His face and to pursue righteousness.  

Quoted section of Matthew Henry's commentary re Genesis Chapter 5:

https://www.biblestudytools.com/commentaries/matthew-henry-complete/genesis/5.html

All the patriarchs here, except Noah, were born before Adam died; so that from him they might receive a full and satisfactory account of the creation, paradise, the fall, the promise, and those divine precepts which concerned religious worship and a religious life: and, if any mistake arose, they might have recourse to him while he lived, as to an oracle, for the rectifying of it, and after his death to Methuselah, and others, that had conversed with him: so great was the care of Almighty God to preserve in his church the knowledge of his will and the purity of his worship.

In mankind's narrative, the second generation (Cain) chose sin, not unlike his parents, Adam and Eve.  But, unlike Adam and Eve, God cautioned Cain after his misgiving, to choose good (God) and he would be accepted - but Cain does not.  He lets sin fester until his anger drives him to murder, him of who Cain was jealous.  Sin, when unchecked, when unrefuted, when unrepented, leads to obsession, and ultimately leads to death.  Genesis 3 and 4 are in the Bible for our instruction - to know mankind's beginning, to know our God, and to know what happens when sin is chosen instead of obedience to God.  

From Adam and Eve in Chapters 1-3, the next generation of humans is introduced at the start of Chapter 4, with the firstborn and the second born of Adam and Eve (Cain and Abel, respectively).  We read both Cain and Abel work and bring an offering to the Lord, but they are very different offerings.  One approaches God correctly (Abel) bringing a choice sacrifice, and one approaches God in a way to evoke God's response of "no regard" (Cain).  But our loving God does not leave Cain in his sin of an unacceptable offering, God counsels Cain in that moment how to be in right relationship with Him and warns him that sin desires to well up in Cain.  The choice now is that of Cain.  

After God pronounces the curses to Eve and Adam, He now drives them from the garden of Eden.  The garden had abundant food, beauty, and joy, but the greatest gift in the garden before was God's presence.  Banished from the garden, the first two humans are now to cultivate food and live in hardship, in stress, and with pain.  Death would await their future, but the relationship with God was not over.  As will be common throughout the Old Testament, God makes commandments and covenants with His people, they are unfaithful, God sends them into exile, and God brings them back in restoration.  The greatest restoration plan arrives for all God's children, in the Messiah, Jesus Christ, who came to earth on a rescue mission, to die on the cross for our sins, and be resurrected to life again, a foreshadowing for all God's children who submit their lives to Jesus Christ.  

"For if many died through one man's trespass, much more have the grace of God and the free gift by the grace of that one man Jesus Christ abounded for many."  Romans 5:15

For the direct justice of the law God established, with a broken commandment, is due the immediate punishment and God speaks it to them after the offense.  God brings respective curses upon the serpent, upon the woman, and upon the man.  God proves to mankind in this who He is and what His law means.  There is also a foreshadowing of what is to come, in the fulfillment of God's plan on Earth and for His kingdom with respect to mankind, and with respect to Jesus' defeating death so all God's children can live, and how Satan will be defeated in the end by God.  One thing is for certain, when you go against God's command, there will be pain.  

Satan tempts Eve and Adam to distrust God.  They entertain the serpent.  And in choosing what the serpent said to follow, they sinned and disobeyed God, which had a disastrous effect, primarily, on their relationship with God.  And in their punishment, God is just.  And in God's continuing love for them, God is faithful.

A serpent appears to Eve in the garden - to oppose God and to encourage her to oppose God.  The serpent somehow knows the command that God spoke to Adam, and then pushes Eve to doubt God's command.  

One to help Adam shoulder the load, and a companion, the first woman on Earth is created with the hand of God, with particular attention and formed by God's hand.  God also sets the standard here for marriage: one man and one woman.  The charge before them is great: to exemplify God on Earth and to exemplify God to each other.  The charge is the same for every one of us.

Article:
https://rabbiyeshua.com/articles-by-kehilat/item/49-divorce-remarriage