The heart of the prudent getteth knowledge; and the ear of the wise seeketh knowledge.
A wise person seeks knowledge.
A wise person uses that knowledge to make wise choices.
A marriage is blessed by wise choices.
So, how does one gain wisdom? Well, studying God's Word is the best place, but you can also gain wisdom by talking less and listening more. I'm not just talking about listening to hear, but listening with the intent to understand and gain knowledge. listen for what your spouse isn't verbally saying, but may be saying with his body language or tone of voice.