1. I think you have to go into it mutually looking to the long term, and keep “divorce” out of your vocabulary. I think it would make a big difference in marriage statistics if the partners agreed that divorce was not an option; this would cause each to realize that they were going to be with this person for the rest of their lives, so they better work it out! Naturally this requires humility and self-sacrifice at times.
2. What is the institution of marriage? The answer to this question for you will decide the parameters of “success in marriage” for you. If it is only a legal contract for shared liability and property ownership or a symbol of status, it will be dissolved as soon as these benefits cease to outweigh the costs.
3. Marriage is under attack in modern entertainment. How many television shows or movies aired/released in the last 5-10 years have had any couples with a healthy marriage in it, even as supporting characters? I struggle to think of any. I find it humorously ironic that the only time marriage seems to be mentioned in a favorable light is as regarding same-sex marriage.