Adam and Eve
Adam and Eve were two of God's most prized creations, whom he gave refuge to in the Garden of Eden. After Lucifer's corruption of Lilith, God banished Adam, Eve, and all of humanity from the Garden. Some time after their banishment, Eve gave birth to Cain and later Abel, giving rise to a bloodline that would reach all the way to Sam and Dean Winchester.
After learning Cain plans to wipe out his entire bloodline, Castiel reminds him he is Adam and Eve's first born, and is undergoing a seemingly impossible task. Cain explains he would be culling 1 in 10 of every living human.
Drinking tea together in the Men of Letters Bunker library, Rowena regales Chuck with stories of when Crowley / Fergus was a child and would run around their village naked, reminding Chuck that Adam and Eve were the same way.
When Jack consumes the Occultum and finds himself in a strange wooded area, he is greeted by a young girl who tells him he is in the Garden. Asking if she means Eden, like Adam and Eve, the Girl tells him they were God's most prized creations before He banished them, and mankind, from the Garden.
Adam and Eve in Lore
Adam and Eve were created by God in Genesis. When the serpent temped them to eat forbidden fruit from the Tree of Knowledge of Good and Evil, they were banished from the Garden of Eden by the archangel Chamael.