There are many hazards in the road of life, and surviving them as a couple takes a lot of effort. The partners might feel they have done an excellent job weathering the worst experience of their life, but they turn around and find something else is blocking their path. The obstacles can come constantly to those who are unlucky, and they might eventually tear the two apart. Clinging to each other might be their only recourse, but doing it with the knowledge they will eventually win through the bad times is what every couple really needs. By finding a new view of life, their relationship can be renewed.
When bad times hit, it can be emotionally, physically, or financially devastating. Few people are able to see a silver lining, and their struggles are very real. Their ability to overcome it might depend upon how well their partner supports them, and they will need to understand how they are seeing the outcome if they are less upset over the issues. Being able to share a vision of a happy future is what will keep the two together.
Devastation in any area of life will have consequences, and it could take a couple years to work through them. Being able to see past the immediate difficulties could be something one partner excels at, and the other person will rely on their optimism. If they lose that view, they could endanger the relationship or weaken it considerably.
Sharing a life with someone else is often a boon when bad times hit, and couples have often noted that their partner was the person who got them through a personal crisis. While they should be able to see a better future on their own, relying on the vision of their partner during the darkest times is a way to sharing the burden that besets both of them.