Marriage is still relevant in our today's society. It started as early as the time of creation by God creating male and female, also by removing a rib from the first man to form the woman. It cannot be out date so long as man and woman lives on this planet earth.
People in relationship should get married for the benefit of their children. People should not get married for the benefits of tax, moral reasons and religious customs etc, rather marriage should be between committed couple enough coming together in mutual agreement to live together when it is good and the condition is not alright. They should also love each other unconditionally. Having marital certificate is equally good for official proof and documentation.