Sadhguru
Why do we get married, and why does a marriage need to be formal?
Marriage is made by you, not in heaven
Marriage is made by us to meet our physical, psychological, emotional, social and economic needs with one person we can depend on. If you understand it is made by you for your well-being and take responsibility for who you are, you can make it work.
Formalizing marriage is so that whenever a little friction comes, you don't fall apart. It is a small tying up so that things don't fall apart easily.