I don't know that I would say that God dismisses the men having multiple wives in the Old Testament. Remember, in this series we've been learning about the two sides of God's justice. The retributive side does have a "getting what you deserve" angle to it. And not one of the stories in the Bible of men with multiple wives is without serious consequences. The children of the various women are almost always at odds with one another. Jealousy, conflict, even murder are common occurrences among these family stories.
Also, we were looking at just one moment in David's life where he experienced consequences for his sin of adultery. If we were to look at other stories, say 2 Samuel 6, we would see David experience the consequence of not following God's instructions for how to move the Ark. Regardless of the sin, there are always consequences. And God never dismisses our disobedience. He forgives us of our sin when we ask, but He never dismisses our sin.
Obviously, this is a heartbreaking situation. First, don't underestimate praying for your friend and her husband. Second, if they both are followers of Jesus and attend Gateway, recommend meeting with a pastor for marriage counseling. Finally, if there's resistance from him, this book (which I haven't read) may be of help to her.
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