Relationships require consistency. This does not mean, however, that relationships shouldn't have a dash of spontaneity in them. This only means that relationships should be stable and constant.
Consistency, however, is difficult to have in relationships because people will not be the same every single day. One day, a person may be moody and angry. On another, that same person might seem like the happiest person on earth. When both people in a relationship find consistency, they will have a happier relationship because they will know what to expect from each other. It is difficult to maintain a relationship that is always "up-down-up-down." Both people involved have to know what is going on in each other's life, so that they can maintain their relationship accordingly.
Life is full of unexpected circumstances and events. We try to plan for them, and we sometimes try to forecast them so we can avoid some of the bad events or circumstances, but it is still difficult to do so. We crave consistency and stability in our lives. In relationships, we want that consistency because it allows us to have a peace of mind about our relationship. We don't want to have to keep thinking about the actual maintenance of the relationship, because that is mentally exhausting. On the other hand, usually we can't have a relationship that is naturally consistent because generally the two people involved in a relationship do not have exact, or even similar, personalities.
Those who are not consistent in their relationships find themselves jumping from one partner to another. They do not know what they want, and as a result they can't lead lives alongside with others. Consistency is a word that is unknown to these people; whatever happens, happens. Yet, most relationships can have consistency in them if both partners are willing to make their relationship stable. Sometimes, it only takes a little bit of better communication for a couple to make their relationship more consistent. Consequently, it is also important that both partners talk to each other on a regular basis about where they want their relationship to go. This communication ensures that both partners are on the same page, desiring similar goals for their relationship, and want consistency.
Consistency does not come easily to most people. But, hard work generally results in good consequences. Consistency produces happy couples who usually get what they expect from their relationships.