When we are first introduced to Cabot Searcy, he's just Benton Sage's charming, playboy roommate. He seems irresponsible and cavalier, but not necessarily dangerous:
Cabot Searcy had the kind of confidence that made it difficult for whoever was around him to pay anyone else any attention at all. When Cabot began to speak, the entire room centered on him. When he laughed, the entire room began to laugh. When he seemed angry, the entire room scowled and frowned. And girls, well, they practically lined up outside of Cabot and Benton's room, waiting their turns to be touched by greatness. (8.18)
However, things quickly change for Cabot. After Benton's suicide, he becomes brooding and obsessive after discovering the Book of Enoch in Benton's possessions. As he starts to read and form his own theories about this text, he really goes off the deep end. It's quite a fall from grace, if you will, which is fitting since Enoch's main angel is fallen himself.
Cabot becomes more and more religiously inclined as he grows older, and things just get worse after he marries Alma Ember and she has a miscarriage. He becomes convinced that it all happened because of God:
This had not been the first time Cabot had blamed God for the loss of his child. In fact, he had begun to write down lists of all the world's evils, as if he were building up an army of words to fight some heavenly battle. (16.8)
Cullen lists made-up zombie book titles, Cabot lists "the world's evils"… to each his own, we suppose (though there also just might be a paper topic in there somewhere). But hold up: The fallen angel in the Book of Enoch is named Azazel. And do you know how else is named Azazel? A goat in the Bible who gets all of Israel's sins placed upon his head, and then driven from the land. Israel's sins… "world's evils"… we're thinking those sound like they're pretty similar.
And just as the goat is driven out in Leviticus, Cabot's fanaticism renders him unable to engage in the real world, which winds up costing him his marriage to boot. Unable to accept this, Cabot heads to Lily to get Alma back, which leads to him kidnapping Gabriel. Kidnapping Gabriel is initially a mistake—Cabot's target is Cullen, in revenge for dating Alma—but once he learns Gabriel's name, well, let the messages from God ensue. As far as Cabot's concerned, this Gabriel and the biblical angel are one and the same.
Here's the most interesting thing about Cabot as an Azazel figure, though: The biblical goat dubbed Azazel was basically randomly designated to carry the super heavy load of the entirety of Israel's sins. It was between him and another goat—who got designated God and then sacrificed (so wasn't necessarily having a great day either)—and the way which one would get the sins and which one would get sacrificed was decided was basically by coin toss. In other words, this comes down to luck.
Cabot, then, can be understood as having a pretty significant change of fortune in this book. He starts out at the top of the pecking order, but through landing Benton as a roommate and all that stems from this (Benton's suicide, his family's disinterest in sorting his belongings, and such), Cabot's world falls apart. He may not be driven from the country, but he is driven from life as he's always known it. And just like his hooved biblical counterpart, we're thinking he never gets to return.