The answer is simple. According to Wikipedia Lucifer is derived from the Latin and was most often applied to the planet Venus, meaning morning star. Venus, if you know anything about astronomy, is the brightest planet visible from Earth. It is only visible as the Sun sets or as it rises, hence is called variously the evening or the morning star. In its morning star incarnation it was given the name Phosphorus (see Lucifer) by the Greeks, and as the evening star it was called Hesperus. It would seem the ancients thought they were dealing with two different planets, or rather, gods.
“Lucifer, ( Latin: Lightbearer) Greek Phosphorus, or Eosphoros, in classical mythology, the morning star (i.e., the planet Venus at dawn); personified as a male figure bearing a torch, Lucifer had almost no legend, but in poetry he was often herald of the dawn. In Christian times Lucifer came to be regarded as the name of Satan before his fall.” (see Britannica: Lucifer)
So there you have. Lucifer was the name given Venus when in the morning it heralded the arrival of the Sun; hence the name, Lightbearer. It was later Christians who added a second layer of meaning when they decided all pagan gods were demons. It seems your fore-bearers didn’t stop believing in pagan gods, they just gave them new clothes to wear and provided them with a new agenda.