Of all of the pictures that God could have chosen to show His love for us, He chose marriage.
Husbands are told to love their wives as Christ loves the church. Wives are told to be submissive to their husbands as unto the Lord. Here is what the Lord is essentially saying: "Hey world, want to know how much I love My people? Check out the way that Christian husband loves His wife. Hey nonbelievers, want to see how much My people love Me? Check out the way that Christian wife loves her husband."
From that perspective, can't you see how bad it is when Christians divorce? It devastates our witness. We tell the world how to live—how to be changed by Jesus—but then we can't work out our problems in our own marriages. It should not be so.
God has chosen marriage as a representation to a lost world. Therefore, when you have a strong marriage, you are a powerful witness. How did God show His love for His bride, the church? By sending His Son Jesus to die on the cross for us. Talk is cheap. Words are easy to say. But God put His own Son on the cross to die in our place, in order to demonstrate how much He loves us.
"But Greg," you might say, "Those are tall orders! There's no way we can love like that on our own!" That's true; we can't.
We need the Holy Spirit's power to be the husbands God has called us to be. We need the Holy Spirit's power to be the wives God has called us to be. We need the Holy Spirit's power to be the parents God has called us to be. We need His help.
So be filled with the Spirit, walking thought by thought, decision by decision, act by act under His control.