Lilith isn’t found in the Christian Bible, not the King James version in any case. But she is found in numerous other texts, one being the Alphabet of Ben-Sira - an anonymous medieval text which was attributed to the writer of Ecclesiasticus. In this text she is said to have been Adam’s first wife. So how came she to be supplanted by Eve?
When God made Adam, He formed him of the dust of the ground and breathed life into him. In the same way Lilith was made. Lilith was made to be the companion of Adam, but they didn’t quite hit it off. As soon as he wanted to lie with her, she refused to be under him. But Adam also refused to be on the bottom, saying that Lilith was made to be his companion therefore he was superior and should be on the top. Lilith insisted that they were equal for they were made in the exact same way.
Their argument proved to be their union’s downfall for Lilith spoke the Ineffable Name and flew out of Eden. Adam cried out to God that Lilith had refused him and ran away. God ordered three angels to fetch her back and he told Adam that if she did not come back, 100 of her children would die every day; but if she did come back all would be good.
The angels caught up with Lilith and told her of God’s decree, but she refused to go back to Adam. When they threatened to drown her in the sea which was flying over, she ordered them to leave her alone and said she would cause sickness in infants. Still the angels insisted she go back and still Lilith refused, going on to say that if she ever saw those three angels’ names or forms carved into an amulet, she would leave the baby untouched by sickness. Then she agreed to have 100 of her children die every day.
When Lilith did not come back, God put Adam into a deep sleep, took one of his ribs, and made Eve from it to be Adam’s companion. Despite having 100 of her children die every day, Lilith went on to mother thousands of demons and is now widely known as the mother of all demons (for those who acknowledge her existence).