In Poker they have a phrase "going all in." This is an important part of marriage as well. You have to "go all in" to make your marriage successful. You can't go half way. You can't give it a try or give a half-hearted effort. You need to give all that you have to give.
This also means that you can't hold anything back. You can't hold back a part of yourself that you're not willing to share. It means being open and honest, and even making yourself vulnerable in a way, because you are trusting another person with the deepest part of yourself.
You cannot have the mentality of having a "plan b" in case the marriage doesn't work out. This means not running home to family any time an issue arises. It also means you have an exclusively intimate relationship with your spouse. You don't keep close relationships with others of the opposite sex, which can lead to an affair, or to thinking that you wish your spouse would be more like them, etc.
We actually knew a married woman who had a life-sized stand-up cardboard cutout of a professional football player she had a crush on in her workout area. This person said that she had told her husband that if that football player ever came knocking on their door for her, she would be gone. Even in joking, that mentality is wrong. Once a person has married, they have agreed to a mutually exclusive relationship "until death do them part."
In poker if you "go all in" you can win some major money depending on the stakes, your cards, and how you play the game. However, if you lose, you lose everything you brought into the game.
In marriage the stakes are high. Think about the cost of a broken marriage. In the case of divorce, there are many costs, financial costs, and emotional costs. This is especially true where there are children involved. There are many emotional costs on the children of divorced parents. But, not only the immediate family, but also extended family are affected when there is divorce.
However, think about what is at stake to win with a happy, healthy marriage. Happiness, love, companionship, trust, having someone to share life with, etc. Also, having children that are happy, healthy, and secure. The benefits of a happy marriage are definitely worth the effort. Just make sure you "go all in" and work with your spouse to create the life you want to share together!