The devil could change. He was once an angel and may be evolving still.

Peter’s line plays on the Christian mythos of Lucifer as a fallen angel to argue, wryly, for the possibility of change even in figures we treat as irredeemably evil. By reminding readers that “the devil” has a history—once “an angel”—the quote undermines fixed moral categories and suggests that character is not static but developmental. The final clause, “may be evolving still,” adds a modern, almost scientific vocabulary (“evolving”) to a theological image, implying that transformation can continue in unexpected directions. The effect is both skeptical and humane: it cautions against assuming anyone is beyond alteration, while also hinting that change is not automatically improvement.