"Herodias harbored a grudge against" John the Baptizer (Mk 6:19) "because John had told Herod, 'It is not right for you to live with your brother's wife' " (Mk 6:18). So Herodias got Herod to arrest, chain, and imprison John (Mk 6:17). However, she was not able to get Herod to kill John until "Herod held a birthday dinner for his court circle, military officers, and the leading men of Galilee" (Mk 6:21). We don't know, but Herod may have been drinking too much alcohol. We also don't know, but Herod may have been lusting for the dancing daughter of Herodias. (Herod was already living in a lustful, adulterous relationship with Herodias.) Possibly Herod was "high" and even more susceptible to lust. To impress the girl and everyone else, Herod swore that he would give her whatever she asked for, even to half of his kingdom (Mk 6:23). This may not have made Herodias happy since a younger woman, her own daughter, was being favored rather than she herself. Herodias, nonetheless, used the situation to get John beheaded (Mk 6:24). Herod still could have eaten his words. "Yet because of his oath and the presence of the guests, he did not want to refuse her" (Mk 6:26).
What are the makings of a murder, or of other mortal sins? Sexual sins, pride, grudges, compromises, alcohol, more sexual sins, rash statements, more pride. Satan knows how to weave a web. Will you be trapped in it and damned? Or will you repent?