Who is Satan, the devil? What is he? Where does he come from? Well, most people identify him with the
Lucifer of the Bible who is mentioned in the 14th chapter of Isaiah. It says:
How are you fallen from heaven, O Lucifer, son of the morning! How are you cut down to the ground, who did weaken the nations! For you have said in your heart, I will ascend into heaven, I will exalt my throne above the stars of God: I will sit also upon the mount of the congregation, in the farthest sides of the north: I will ascend above the heights of the clouds; I will be like the most High. Yet you shall be brought down to sheol, to the sides of the pit.
Before we can understand this interpretation, we have to understand where angels come from in the first place—and why they even exist. We’ll find a fascinating discourse on the subject in the beginning of the Epistle to the Hebrews.