Helps you have stronger morals

Not to say that the only way to be a moral person is to get married, but living a married life involves a lot of challenges. When people get married and start to build their own family, they experience problems that are not commonly experienced by singles (such as providing for children, paying for debt that is not your own, etc). Because of this, married people are given the opportunity to overcome unique challenges, thus allowing them to become stronger in their morality.