Genesis 1 to 6.

The order of Genesis 1 to 6 has a purpose.

Genesis 1 tells us what it was like before He created; only God existed; The Father, Son, and Holy Spirit.

He started creation with light. There was nothing but God before that. There is no gap theory.

Then from light comes the earth. Then the earth is populated with humanity literally being the last creation but all of it was done for us.

Genesis 2 recaps Genesis 1 and then tells us about Adam; a man set apart from the rest of humanity in a special set apart place. Genesis 2 is not a separate creation it is the detailed telling of God's first high priest in the garden temple.

Genesis 3 tells of the fall of mankind. Adam was the federal head of humanity and when he fell he took us all with him.

Genesis 4 tells us of the bad seed line of Cain. This seed line did not survive the flood; however, since man is corrupt, it did restart.

Genesis 5 tells us of the righteous seed line that led to Jesus. 

Genesis 6 tells us what happens when the righteous seed line mixes with the corrupt seed line. This is why God told Israel not to mingle with those surrounding Israel.