Of all the Herods in the bloody family of that name, Antipas receives the most prominent treatment in the New Testament — and this because of his connection with John the Baptizer.
Though Antipas was married to the daughter of an Arabian king, en route to Rome (cir. A.D. 29), he became infatuated with Herodias, his brother Philip’s wife. They entered into an intrigue whereby the ruler would divorce his wife, and Herodias would divorce Philip. Antipas and Herodias then “married” one another (cf. Mark 6:17; see Josephus, Antiquities 185.1ff). Note that word “married”; it will be significant momentarily.
Both Matthew and Mark record the fact that a controversy between Herod and John the Baptizer developed over this matter. John, in a direct confrontation with the ruler “said [an imperfect tense, suggesting repeated rebukes] unto Herod, It is not lawful for you to have your brother’s wife” (Mark 6:18). The rebuke cost John his life!
There are a couple of important points to note here. First, observe that the union of Antipas and Herodias is, in some sense, characterized as a “married” relationship. Does the use of this term legitimize the union? It does not. John described the situation as “not lawful.” The verb echein, rendered “have” can be used in this sense: "to have (use) a woman (unlawfully) as a wife (Thayer, Greek Lexicon, p. 266). Frequently words are employed in common parlance, rather than in a technical sense. Antipas and Herodias were “married,” insofar as society viewed the matter; from the divine vantage point, though, the relationship was unlawful. Circle both “married” and “not lawful” (Mark 6:17-18), and connect them with a line. A mere ceremony does not transform an “unlawful” union into a lawful one.
Now, what must one do when he finds himself in a relationship (even though sanctioned by civil procedure) that is “not lawful”? The answer is clear. He must abandon the sinful activity. True repentance demands nothing less.