Adam C. English, the author of a new book on St. Nicholas, describes the man as an "every saint" who appealed to the common Christian:
Many saints are biblical saints, or they're usually remembered because they were martyred or they performed some tremendous miracle. But Nicholas stands out because he didn't do supernatural miracles. He wasn't martyred. He was more of a social activist, politician, businessman, lawyer, judge, and protector.
English goes on:
He also was a man of God who stood up for his faith, who challenged pagans, who was willing to confront people. Into the Middle Ages, he's depicted using the whip against Christians who have fallen astray. He may bring punishment as well as good things—to determine, in other words, whether we've been "naughty or nice." We tend to downplay this side of him—a true and faithful judge of character and someone who is standing for the faith.
The Dish 