Marriage is a strange institution. Moulded more by influence of the church than by the practitioner. It ties two people together in an established society. For better, or for worse.
The reason marriages fail. If I may be so bold as to offer further opinion; is that the goal of marriage is often confused. Some people think it is about sex. To some it may be, but in reality, sexual drive is a young persons domain, and marriages are meant to last a lifetime; so I don’t really think sex is a reason for marriage. Some people think it is about love. But love can be as ungraspable as the mist. It is there, sure, but what does it mean? To some it is about companionship, supposing that good friends and family mean nothing compared with someone you have legally committed to.