I asked my husband, who is Casca Servilius, aka LuciusFlaccus Valerius, if he could tell me the reason behind the confusion on Lucifer and Satan.

The name 'Lucifer' never actually appears in the Bible, but is read to refer to 'The fallen morning star'. In the Middle Ages, many priests confused this 'Lucifer' or 'morning star' with Satan, who is explicitly mentioned in the Bible. Many read 'morning star' as a reference to Satan himself.