Everyone quotes 1 Peter 3 for marriage. Nobody quotes the part with the instructions (vv. 8-12):
1. Same team
2. Don't return fire ("insult for insult")
3. Bless instead
4. Guard your tongue
5. Chase peace
The famous verses are the posture. These are the practice.
Want to bless your marriage?
* Thank your spouse for doing the dishes.
* Thank your spouse for filling up the car.
* Thank your spouse for mowing the lawn.
Thank your spouse for all the things they're SUPPOSED to do.
Everyone needs to feel appreciated, even for little things.