It is very important for the survival of the Republican Party to adopt the policy of getting the government out of marriage, period, in order to retain their small-government beliefs and also gain the support of the gay community.
But on a religious level, it is also important for young Christians to heed the words of Romans 1:32. Many of the current generation's Christians have been brainwashed by pop culture to support gay marriage, and that's a dangerous trend.
Even beyond the argument that Jesus Himself affirmed male-female marriage in Matthew 19:4 when he said, "Haven’t you read that at the beginning the Creator ‘made them male and female'?" there are other arguments to be made.
I gave the following arguments to a Christian supporter of gay marriage, and after she read these, she told me, reluctantly, that I changed her mind and that she no longer supported gay marriage. She felt guilty about it, but she knew I was right. One down, countless more to go.
God made the human body and he made each piece for a purpose and for that purpose only. The only reason you can see is because your eyes are connected to your brain. If your eyes were on your elbow, they wouldn't work unless your brain was also in your elbow. There is a clear design to everything. A penis and vagina together serve a purpose: procreation, and also attaining oneness with your spouse. A penis in anything else serves no purpose but base, animalistic pleasure.
God made animals male and female. When God made Adam, He saw that none of the animals was suitable for him. That's why God made Eve: to make someone suitable for Adam to be with. If the gender of Eve did not matter, God would not have created gender in the first place. God specifically wanted males to be with females. If he wanted males to be with males, he would have made pregnancy possible when a male has sex with a male, and just not created females at all. But God made females specifically because that's what he wanted males to be with; not other males.
As Christians, we see that the history of the world is a history of increasing corruption. We know that Satan is always trying to corrupt or destroy God's work. Satan corrupts the minds of those who care more about convenience than about the lives of babies. Satan gets into the minds of politicians who believe it's okay to steal as long as you give the money to those who they think deserve it (even though God said stealing is wrong, period). Satan has corrupted humans' view of sex, too. He has made it so that kids believe sex on the third date is good, as opposed to sex after marriage. Satan has made it so that society doesn't treat marriage with as much respect as they once did, with 50 percent of marriages ending in divorce. In short, Satan corrupts society. That's his intention.
Society's lackadaisical attitude toward gay sex is due to Satan's wanting us to feel that way. And there is a clear reason Satan would want us to believe gay sex is okay. So why, then? Because Satan hates life. He is of death. He wants to spread death (that is, disease, sickness, murder, etc.). Satan's goal on Earth is to corrupt all of God's Creation, to hinder all of God's goals. And what is at the heart of God's creation? What is the source of life on Earth? Male-female sex (intended to be for marriage, of course). God uses male-female sex to create and to advance His goals and further His creation. Satan uses male-male or female-female sex to destroy, to tamper with and corrupt God's Creation and God's goals. This is why gay sex is so widely accepted in today's corrupt society (and as we know, society has become more and more corrupt because of Satan). Do we think that society is becoming more and more corrupt except for this gay-sex thing? That that's just the one area in which we're advancing as a society? That it's not a result of Satan's mischief, that Satan "missed a spot" when trying to corrupt society?
Look at it this way: If gay sex is good, then that means Satan would only support its opposite, hetero sex. But then that would mean that Satan is in agreement with God in that area, but that's impossible because Satan is the opposite of God in every single way. He and God, by necessity, cannot agree with each other. If gay sex is good, then that means God's original creation of males and females for each other was bad. It means that Satan wants male-female marriage/sex, and that God wants gay sex. If that were the case, God would have created one gender only.
We Christians cannot approve of gay marriage (and the gay sex that that implies), just as we cannot approve of any sin, or else we're just as guilty of that sin (Romans 1:32). Of course we can be friends with gays; gayness itself is not what is sinful; it is falling to the temptation of acting upon that gayness.