I mentioned these Four Qualities earlier of Generosity, Morality, Wisdom and Saddha or Confidence/Faith. Think about them.
Morality. Let's say you love your spouse and you are faithful to your spouse, but they are not faithful to you. They want to go off with a different guy or girl regularly and you are left home alone. Is this going to make you happy or unhappy? It is pretty obvious. This is an area of Morality. If the Morality, or ethics of a couple are very different, then how are you going to stay in that relationship. If the morality or ethics of a couple are the same, then you are going to stay with that person and they are going to stay with you, you are not going to go flirting with other people, neither is your spouse, great! That is going to strengthen your relationship.
Generosity, the second one: you like to give; you like to give to your spouse. But your spouse likes to take and take, you give but they just want to take. Is that going to make you happy in the long run? No. There is also the outward Generosity. You like to help your neighbors, you like to help your friends and family. But your spouse or partner doesn't like to do this. They like to stay living in their own little world. They don't like to give money away or anything, but you like to give. So Generosity. If you are both generous, on a similar level, you both like giving, you both like helping, doing charity work together and so on, then of course, your relationship gets stronger.
Wisdom. What happens when you both have the same level of Wisdom? You can talk with each other. If one person is fairly wise, yet the other person is fairy dumb, what happens? The wise person talks at the other person, there is no conversation back and forth on the same level, because the other person can't do it on that level. So instead of being friend-friend relationship it becomes what they call a teacher-student relationship. This doesn't work in the long run. Because dissatisfaction occurs, the person down below is going to be tired to be talked at, told what to do and everything else. And the person on top gets tired of not having somebody they can communicate with. So Wisdom, the third one, if the Wisdom is the same level you can discuss things with each other, you can share with each other, you can debate with each other and you can really have conversations that both of you can benefit from.
Saddha, the Pali word meaning confidence or faith, generally this is the spiritual practice. What happens if you both are Buddhist meditators? Great! You can go to retreats together, you can share together, you can go to moon days together, you can visit monasteries together, you can talk about the same things together, and so on. What happened if one person is a Buddhist and the other person is a Muslim? You are not going to share going to the same temple together, you are not going to share the same religious practices together. Often you may not think the other person is very smart for some of the beliefs that they have and immediately there is a separation, it is not going to make for a strong relationship. But when the Saddha is the same, the relationship gets stronger in that way, too. So that is pretty obvious in a nutshell, a very simple way to show how important these Four Qualities are to make for a good relationship, a good friendship, in finding the right partner and sticking with the right partner.