Marriage is defined as a legal union of man and woman as a husband and wife to spend the rest of their lives together as one.
I think you should get rid of the word "defined," and actually...get rid of this whole sentence.
As
it is a life-long promise of two people, joining together as one to depend on each other and share every thing they possess, marriage is
considered as one of the most significant decisions in many people's lives. (now write a sentence that introduces the idea of how some marriages are successful and others are not.) Sustainability of happy marriage is significant in order to achieve relaxation and pleasure in
life, and...
Marriage is
like difficult homework given to every person
, and it is their duty to discover the
best ways to support one another to create a good and comfortable marriage.This does not have many mistakes! Keep at it. I think you could add a good attention grabbing, interesting sentence to the beginning of the first paragraph, too. It is a cool essay; I like the structure, where you write about communication, compromise, and love at the end of that first paragraph and then explain them in the body paragraphs.
Perhaps you should acknowledge that in modern times marriage is no longer always man and woman. Perhaps you should also acknowledge that marriage has historically kept women in subservient roles, but that gender equality is transforming marriage.