Denying gay couples to wed is a violation of religious freedom; considering the fact that religious and civil marriages are different institutions. The biggest reason why gay couples are being denied to get married is because major religions regard homosexuality as a sin. Contrary to this, the First Amendment of the Constitution states that ‘an individual’s religious views or lack thereof must be protected.’ If gay couples decide to forego church weddings and instead, have a civil union, the government needs to adhere to their request.
"Polling data states: most people in states with same-sex marriage say it has not affected them, and in those states, as throughout the country, as people get to know gay and lesbian couples, they are more likely to support marriage rights" - ERIK ECKHOLM