Imagine what consistent kindness could do in marriage. I've seen it turn desperate marriages around. Yes. It takes strength and perseverance, but it is worth it.
God did not promise marriage would be easy, but many of us were fooled by the euphoric "in love" experience that happens in the beginning of a relationship. After that fades away, and it always does, the real work of love and marriage begins. This is where we must choose to intentionally be kind.