The universe was a tangled mess.
So over the course of six days God created the heavens and earth, separated land from water, day from night, created the sun, stars and moon, grew plants and tree, created all living things as well as human beings in his image, and then took the seventh day off, making it holy.
God told the first two humans — Adam and Eve — to not eat from the Tree of Knowledge, but after being tempted by a serpent, they ate from the tree, which made them ashamed of being naked.
God wasn’t too happy with them and sent them out of the Garden of Eden, into a life of hard labor.
Adam “knew” Eve, who then gave birth to two children — Cain (who became a farmer) and Abel (who became a shephard).
Later on in life, Cain killed Abel because God loved Abel more.
Cain felt bad and wanted someone to kill him in return, but God put a mark on him, keeping anyone from harming him.
Eventually Eve gave birth to another child — Seth (meaning “God has given me another seed to replace Abel), and both Cain and Seth had many decendants.
These decendants multiplied, and because the human race.
God realized that pretty much all the humans were evil at heart and decided to destroy all living things on earth, but Noah convinced him otherwise.