Marriage is defined as "the legally or formally recognized union of a man and a woman as partners in a relationship." This means marriage is not for a woman and a woman or a man and a man. The controversy that surrounds this has been rising for many years. Even some states have legalized gay marriage but there are a many that have not. Is Homosexuality not a part of God's design? According to Leviticus 20:13, "If a man also lie with mankind, as he lieth with a woman, both of them have committed an abomination: they shall surely be put to death; their blood [shall be] upon them" (http://www.kingjamesbibleonline.org). This meaning that God's intentions are for a man and a woman to be together, and not a man and a man or a woman and a woman. "Even if there is a genetic predisposition toward homosexuality, the behavior remains unnatural because homosexuality is still not part of the natural design of humanity" (Homosexuality 55 ). This meaning that being gay is unnatural. .
'Gay marriage could potentially lead down a "slippery slope" giving people in polygamous, incestuous, bestial, and other nontraditional relationships the right to marry" (http://gaymarriage.procon.org/).Now I know what you are thinking, thats quite farfetched, but is it really. Allowing gay marriage is like letting a baby write on the walls, if one kid does it the rest of them want to do it. "In April 2013, Slate published a plea for legal polygamy by writer Jillian Keenan: "Just like heterosexual marriage is no better or worse than homosexual marriage, marriage between two consenting adults is not inherently more or less 'correct' than marriage among three (or four, or six) consenting adults" (http://gaymarriage.procon.org/).
Gay marriage could lead to more children living in same sex households. This isn't the optimum environment for children, because children need a father and a mother.