Think about who you are in Christ. Your job on earth is to reflect God's glory, ie: show His attributes, stand for what He stands for, love what He loves; hate what He hates (sin). Obama supports abortion and gay marriage. Don't believe the hype. Those are not minor issues, esp. abortion. Jesus said "Suffer the little children to come," not "kill them whenever it's convenient."
Gay marriage is an oxymoron, at least for the Christian. It's an impossibility. Marriage as God defined it was man and woman. After all, it was Adam and Eve, not Adam and Steve. Not to be overly simplistic, but that's pretty clearly God establishing the order of operations. There is absolutely no mention of homosexuality prior to the first sin. And every mention of gay lust/sex from that point on makes the behavior a sin. Not to say a worse sin than adultery or sex outside of marriage, but still sin. So we don't celebrate the sin by endorsing it as a marriage.
Those should be deal breaker issues. You vote for Obama, you sneer at God's holiness.
Next, I've heard excuses of "we can't vote for a Mormon." That's just inane. Mormons happen to share a TON of Christian beliefs. But regardless, you want the guy who will do the best job to get our country rolling. If you use Romney's Mormon faith to rule out voting for him, you just confirm the hypocrisy nonChristians accuse Christians of.
Finally, just for the sake of effectiveness, you almost certainly have to vote Romney. Obama was overmatched by the office of President. He talked a good game and failed to follow thru. By his own standard, he needs to go. "One term proposition." He's right about that. If a sitting president does not make marked improvements in 4 years, he does NOT deserve FOUR more. Same for Romney should he get elected.
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In sum, consider the issues here: Obama is for big government, more and more people relying on government, muddying moral waters, allowing America to promote sin, gigantic increases in what America owes in debt, and no substantial plan for improvement.
Consider also who promotes Obama, who speaks for him, and the one Obama counts on to "bring in the votes"--Bill Clinton. The man who was disbarred, impeached, and disgraced--and he is the Dem's big hitter? Really? Why would anyone believe a thing Bill Clinton says?
Romney is for reducing government's interference and our dependence on government, making right and wrong clear again, cleansing America of the blight of abortion, keeping marriage as a holy institution, and an actual plan for improvement. Please vote intelligently and by faith. Mitt Romney is not a perfect candidate. I'm not convinced he'll even be great, but he will almost certainly be better than Obama. And he will almost certainly make our nation more Christian friendly than it has been in years.