This is a tall order. More than half of all marriages fall short of this ideal. I would argue there are many that maintain their marriages but suffer tremendous strain due to unwillingness to address the weaknesses where love fails or is diminished, causing an environment that is contrary to the marriage ideal.
It’s easy to accuse one or both persons of being too selfish. Is it selfish for a unhappy wife to want the affection of her husband when there is none? Is it selfish of an unhappy husband to expect the emotional support of his wife but not receive it?
There is a place for selfishness. Some selfishness is better identified as our “needs.” Our needs are important and have an effect on how we love another. If no needs are met as were expected, then love can die. Should it die? Probably not, if we only focus on loving as Jesus loved, which is a giving and self-donation without getting it in return. But only God can live this kind of love.
Human beings fall short of this kind of love. And it will always be this way. Marital love is a tall order because it’s unnatural for human beings to accomplish. It’s impossible because we all have needs, and we all have expectations as to how those needs should be met. It’s not for us to discount these needs. But it’s also not for us to excuse our behavior based on these needs.
The key is to accept that we are selfish people throughout our whole lives, and that success in marriage between two human beings is in embracing each other’s humanness as the probability, while mutually striving to become more like that unnatural divine love that is God. We need to accept that 1) we are selfish and need to work on becoming less selfish, 2) only God can love us perfectly, and 3) any human being is going to fail at times in true love. This kind of acceptance goes a long way in how we approach our own needs as well as the needs of the person we love.
There is still the matter of our valid needs that do have to be met, at least often enough to keep us afloat. No person can sustain providing love to another by meeting all their needs, while having no need of their own met. That’s not marital love. Marital love requires both persons participating in the game. When one is down and lacks the ability at the time to give, the other needs to be the stronger one, and vice versa.