A successful marriage is defined by a married couple that works together like a team, and ensures each other's welfare before that of anyone else. A good way to help make your marriage a success if to expect less from your partner, which can help you get more from them. We often can place unreasonable demands on our spouses which they are just simply not able to meet, and get upset when they don't. If we expect less of them, then they'll get into your good books right away.
Hmm... This is a tough question! Every marriage is different and can only be defined according to its parameters. But perhaps this one thing might hold true - a successful marriage is when a couple constantly communicates to each other and understands each other well. They share their thoughts and emotions in an open and non-judgemental way and try to make themselves a better person each day.
A successful marriage is one in which both parties feel the relationship improves their lives rather than detracting from it. Most couples find marriage to be a source of joy as well as challenges, and the ones who get a lot out of their marriages will also put a lot of energy into overcoming the challenges together. There will always be time when a marriage feels like more trouble than it’s worth, but if you sit back and take stock of your relationship, you can consider whether it’s really been adding value to your life by encouraging your personal growth.