This question appears to assume the popular mythology that Satan
is a fallen angel. In fact, the Bible contains no such teaching.
(See “Is Satan a fallen angel?”)  There are two passages that
talk about Satan “falling”.  Luke 10:18 He [Jesus] replied, “I
saw Satan fall like lightning from heaven.”  Here, Jesus is
responding to his disciples reporting how they had been able to
cure people of illnesses. In the Bible, “falling from heaven” is
figurative of losing authority. For example, Isaiah 14:12
describes the king of Babylon as “fallen from heaven” (see also
Jeremiah 51:53), the king of Tyre was “thrown to the earth” in
Ezekiel 28:17, and Israel’s splendor was hurled “from heaven to
earth” in Lamentations 2:1. While the disciples were amazed at
the power they had over disease, Jesus was thinking of his
ultimate triumph over sinful human nature. Elsewhere Jesus
emphasised the link between sin and illness (e.g., Matthew 9:5),
and equated Satan with temptation to sin (Matthew 4:10). In
other words, he is saying