This sermon was hardly needed a decade or two ago, but divorce and remarriage are common nowadays.
I know what it is like to come from a broken home because I have stepparents. I have a stepmother, two kids from my stepmother's side, a stepfather, four kids from his previous marriage, and a half-brother on my mother's remarriage.
Stepfamilies are here to stay. 42% of adults have a steprelationship--either a stepparent, a step or half sibling, or a stepchild. This translates to 95.5 million adults. http://en.wikipedia.org/wiki/Stepfamily
The most deadly and poisonous unhealthy stepfamily relationship in the Bible is that of Herod and Herodias. The story began in Mark 6 (quickview) , where Jesus said, "A prophet is not without honour, but in his own country, and among his own kin, and in his own house" (Mark 6:4 (quickview) , KJV). Within the same chapter an interlude introduced the beheading of the last prophet of the Old Testament John the Baptist was beheaded. The apostles had took up the message of repentance (Mark 6:12 (quickview) ), previously identified with John alone (Mark 1:15 (quickview) ). The two main characters of Mark 6 (quickview)  are contrasted: a good man versus a wicked family, the faithfulness of John and the feebleness of Herod. They are powerfully opposed to each other, their names occurring seven times each in the chapter. The narrative is not intended as a manual on parenting, but the dynamics of parenting are worthwhile.
How are we to remain faithful in the midst of fierce opposition to our values? What does God require of parents? What kind of children are we raising?
17 For Herod himself had given orders to have John arrested, and he had him bound and put in prison. He did this because of Herodias, his brother Philip's wife, whom he had married. 18 For John had been saying to Herod, "It is not lawful for you to have your brother's wife." 19 So Herodias nursed a grudge against John and wanted to kill him. But she was not able to, 20 because Herod feared John and protected him, knowing him to be a righteous and holy man. When Herod heard John, he was greatly puzzled; yet he liked to listen to him. (Mark 6:17-20 (quickview) )
I was less than 5 years old when my parents went through a bitter and sad breakup. She left for overseas with the oldest of the three kids less than seven years old. My father remarried but the new couple lived by themselves, not with us, so we three kids lived with an unhappy grandmother who had to take care of us. We saw our father two or three times a week when he visited and he usually stayed for less than an hour.
My grandmother died when I was 11. With no one to look after us, we were forced to move in with our stepmother, which nobody wanted since she had two kids of her own. The first year went by uneventfully but the reunion was short-lived µ²§ôbut our lives changed, and so did our address, when my older brother uttered these infamous fighting words that made another move necessary. When my stepmother scolded him, he replied defiantly: "You are not my mother!" We literally lived by ourselves for the rest of our teenage years. Many years later, I asked my brother why he said such a stupid thing, he answered, "I was a kid."