It is believed that after seven years of a marriage, the happiness starts wavering. If you get through this, it's most probably going to last. Seven years is a considerable amount of time. A lot can change during these times. You might have gone through a lot. You would've had numerous fall outs, major life style changes, differences with not only each other but the respective families as well and what not. There might have been good times as well as bad times. And to live through these, you could hopefully benefit from the following things:
See the humour in things
Everybody appreciates a good sense of humour. Don't ever let anything get too serious. Learn to laugh at yourself. Try keeping things on the lighter side. You can always save a situation with a good laugh. However, be careful with your timing or you might end up worsening things.
Discover how you express love
This is different for everyone as well. We all have our own way of professing our love. Since it's different for everyone, people often remain in doubt as to whether their partner feels the same way or not. You need to recognize and learn their patterns. Once you do so, you'll see that even though your ways are different, the love is present.