Recently, marriage has been
thought to be
the subject of controversy, with some people arguing that a union between a man and a woman
is part of how the
word itself is defined. As marriage supports procreation and society recognizes the significance of each other's spouse, married couples receive several benefits from the government.
I think this material should be in a body para, not the intro. In the intro, capture the reader's attention and then express your thesis statement after only about 5 sentences.
That material I quoted above should actually be part of 2 different paragraphs: one about the definition of marriage, and another about the government's interest.