"Do you ever try talking about God?" I asked a woman whose marriage was not going well. "No," she answered, "my husband talks a great deal about God, but not in the way you mean. When we talk, we argue and quarrel about bills and every unpleasant thing you can think of." I suggested she try returning thanks at the table, for a start.
Usually, her husband would sit down and glumly pull up his napkin. Finally, one night, she interrupted softly, "I'm going to return thanks." She did the same the next night, and the next, and the next, until, finally, he said: "Okay, it's my turn. I am going to return thanks!"
After that, it was easier to talk about things sanely. They tell me that now their marriage is "in good shape."