Often times we look at marriage from a funnel eye perspective and that shields us from seeing beyond our noses.
Marriage is an institution itself. An institution where death is meant to be the graduation and divorce is dropping out.
For a marriage to last and stand the test of time, then love is just not enough. Yes love is essential in marriage but love is not the only essential ingredient. Love is just one of few essential ingredients.
In my own view, what makes a relationship or marriage so to say stand the test of time asides love is communication and understanding. A couple whose interpersonal communication skill is faulty tend to grow apart despite the love that exists between them thats why it's been said that communication is key to a successful relationship and of course you know marriage is a relationship.
Communication also is not an end in itself but a means to an end. Communication is the foundation of understanding between the couple. When a couple communicates frequently and often about nearly everything, they tend to understand eachother better and strengthen the tie that keeps the relationship together.
Conclusively, communication and understanding is very much essential in a relationship as much as there is love, love doesn't cover it all so my advice to new couples or old couples passing through trouble is try to communicate your feeling, thoughts and reactions to your spouse the right way and establish a foundation of understanding then you'd see that suddenly your relationship would get stronger than it was before